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Sample records for cadmium oxide incorporation

  1. Removal of Cadmium Ions from Aqueous Solution by Silicate-incorporated Hydroxyapatite

    Institute of Scientific and Technical Information of China (English)

    SHI Hebin; ZHONG Hong; LIU Yu; DENG Jinyang

    2007-01-01

    This article reports a preliminary research on silicate-incorporated hydroxyapatite as a new environmental mineral used to remove cadmium ions from aqueous solutions. The silicate-incorporated hydroxyapatite was prepared by coprecipitation and calcining, and silicate was incorporated into the crystal lattice of hydroxyapatite by partial substitution of phosphate. The amount of cadmium ions removed by silicate-incorporated hydroxyapatite was significantly elevated, which was 76% higher than that of pure hydroxyapatite. But the sorption behavior of cadmium ions on silicate-incorporated hydroxyapatite was similar to that of pure hydroxyapatite. Morphological study revealed that silicate incorporation confined the crystal growth and increased the specific surface area of hydroxyapatite,which were in favor of enhancing the cadmium ion sorpfion capacity of the samples. Incorporation of silicate into hydroxyapatite seems to be an effective approach to improve the environmental property of hydroxyapatite on removal of aqueous cadmium ions.

  2. Cadmium-induced oxidative stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Muthukumar, Kannan; Nachiappan, Vasanthi

    2010-12-01

    The present study was undertaken to determine the effect of cadmium (Cd) on the antioxidant status of the yeast Saccharomyces cerevisiae. S. cerevisiae serves as a good eukaryotic model system for the study of the molecular mechanisms of oxidative stress. We investigated the adaptative response of S. cerevisiae exposed to Cd. Yeast cells could tolerate up to 100 microM Cd and an inhibition in the growth and viability was observed. Exposure of yeast cells to Cd showed an increase in malondialdehyde and glutathione. The activities of catalase, superoxide dismutase and glutathione peroxidase were also high in Cd-exposed cells. The incorporation of Cd led to significant increase in iron, zinc and inversely the calcium, copper levels were reduced. The results suggest that antioxidants were increased and are involved in the protection against macromolecular damage during oxidative stress; presumably, these enzymes are essential for counteracting the pro-oxidant effects of Cd. PMID:21355423

  3. A Study of Growth of Cadmium Oxide Nano structure

    International Nuclear Information System (INIS)

    Cadmium oxide nano structure were synthesized by solid-vapor deposition without catalyst. Cadmium Oxide powder was heated to 1320 K in a tube furnace, and the resultant vapor was carried to the silicon substrate zone by an argon flow. Field electron scanning electron microscopy revealed that the product was dendrite-like petals of Cadmium Oxide nano structure. The grown nano structure had random orientations and a grain size of 30 nm. Photoluminescence spectroscopy was conducted to investigate the optical properties of the nano structures. The red-shift direct band gap energy of Cadmium Oxide nano structure was at 548 nm (2.26 eV), whereas that of CdO bulk was at 491 nm (2.5 eV). (author)

  4. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    Energy Technology Data Exchange (ETDEWEB)

    Koparanova, N.; Simov, S. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Fizika na Tvyrdoto Tyalo); Genchev, D. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika); Metchenov, G. (Research Inst. of Criminalistics and Criminology, Sofia (Bulgaria))

    1985-02-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more.

  5. Oxidative Stress in Lead and Cadmium Toxicity and Its Amelioration

    OpenAIRE

    R. C. Patra; Amiya K. Rautray; D. Swarup

    2011-01-01

    Oxidative stress has been implicated to play a role, at least in part, in pathogenesis of many disease conditions and toxicities in animals. Overproduction of reactive oxygen species and free radicals beyond the cells intrinsic capacity to neutralize following xenobiotics exposure leads to a state of oxidative stress and resultant damages of lipids, protein, and DNA. Lead and cadmium are the common environmental heavy metal pollutants and have widespread distribution. Both natural and anthrop...

  6. Oxidative Stress in Lead and Cadmium Toxicity and Its Amelioration

    Directory of Open Access Journals (Sweden)

    R. C. Patra

    2011-01-01

    Full Text Available Oxidative stress has been implicated to play a role, at least in part, in pathogenesis of many disease conditions and toxicities in animals. Overproduction of reactive oxygen species and free radicals beyond the cells intrinsic capacity to neutralize following xenobiotics exposure leads to a state of oxidative stress and resultant damages of lipids, protein, and DNA. Lead and cadmium are the common environmental heavy metal pollutants and have widespread distribution. Both natural and anthropogenic sources including mining, smelting, and other industrial processes are responsible for human and animal exposure. These pollutants, many a times, are copollutants leading to concurrent exposure to living beings and resultant synergistic deleterious health effects. Several mechanisms have been explained for the damaging effects on the body system. Of late, oxidative stress has been implicated in the pathogenesis of the lead- and cadmium-induced pathotoxicity. Several ameliorative measures to counteract the oxidative damage to the body system aftermath or during exposure to these toxicants have been assessed with the use of antioxidants. The present review focuses on mechanism of lead- and cadmium-induced oxidate damages and the ameliorative measures to counteract the oxidative damage and pathotoxicity with the use of supplemented antioxidants for their beneficial effects.

  7. Defects and properties of cadmium oxide based transparent conductors

    Science.gov (United States)

    Yu, Kin Man; Detert, D. M.; Chen, Guibin; Zhu, Wei; Liu, Chaoping; Grankowska, S.; Hsu, L.; Dubon, O. D.; Walukiewicz, Wladek

    2016-05-01

    Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 1021 cm-3 and electron mobility higher than 120 cm2/V s can be achieved. Thermal annealing of doped CdO films in N2 ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ˜1 eV and that the mobility of sputtered deposited CdO is limited by a background acceptor concentration of ˜5-6 × 1020/cm3. The calculations offer an insight into understanding of the effects of defects on electrical properties of undoped and doped CdO and offer a potential to use similar methods to analyze doping and defect properties of other semiconductor materials.

  8. Study of oxide films on the surface of cadmium telluride

    International Nuclear Information System (INIS)

    Study of oxide films on surfaces of CdTe monocrystals is continued by methods of ellipsometry and by absorption in IR-spectral range. Index values of refruction of oxide films, produced by cadmium telluride oxidation in hydrogen peroxide solutions, in oxigen flow at 673 K and by anode oxidation, as a rule, differ essentially in dependence on method of production, that gives evidence of differences in these films composition. Oxide films, produced in oxygen flow, as opposed to films, produced by two other methods, have intensive absorption, characteristic for tellurite group. Film thickness, produced by oxidation in hydrogen peroxide and in oxygen flow, varies within rather wide limits with observance of externally similar conditions of production. By contrast to it, thickness of anode films is regulated reliably by anode potential

  9. Chronic cadmium treatment promotes oxidative stress and endothelial damage in isolated rat aorta.

    Directory of Open Access Journals (Sweden)

    Camila C P Almenara

    Full Text Available Cadmium is a highly toxic metal that is present in phosphate fertilizers, and the incidence of cadmium poisoning in the general population has increased, mainly due to cigarette smoking. Once absorbed, cadmium accumulates in the tissues, causing harmful effects including high blood pressure, endothelial damage and oxidative stress. Oxidative stress is known to efficiently produce oxidized low-density lipoprotein and consequently atherosclerosis, mainly in the aorta. However, the mechanisms through which endothelial damage is induced by cadmium have not been elucidated. Thus, the aim of this study was to investigate the effects of this metal in the isolated aorta and the possible role of oxidative stress. Rats received 100 mg.L(-1 cadmium chloride (CdCl2 in the drinking water or distilled water alone for four weeks. The pressor effect of cadmium was followed throughout the exposure period by tail plethysmography. At the end of the fourth week, the blood cadmium content was established, and the vascular reactivity of the isolated aorta to phenylephrine, acetylcholine and sodium nitroprusside was analyzed in the context of endothelium denudation and incubation with L-NAME, apocynin, losartan, enalapril, superoxide dismutase (SOD or catalase. We observed an increased response to phenylephrine in cadmium-treated rats. This increase was abolished by catalase and SOD incubation. Apocynin treatment reduced the phenylephrine response in both treatment groups, but its effect was greater in cadmium-treated rats, and NOX2 expression was greater in the cadmium group. These results suggested that cadmium in blood concentrations similar to those found in occupationally exposed populations is able to stimulate NOX2 expression, contributing to oxidative stress and reducing NO bioavailability, despite enhanced eNOS expression. These findings suggest that cadmium exposure promotes endothelial damage that might contribute to inflammation, vascular injury and the

  10. Soluble Moringa oleifera leaf extract reduces intracellular cadmium accumulation and oxidative stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kerdsomboon, Kittikhun; Tatip, Supinda; Kosasih, Sattawat; Auesukaree, Choowong

    2016-05-01

    Moringa oleifera leaves are a well-known source of antioxidants and traditionally used for medicinal applications. In the present study, the protective action of soluble M. oleifera leaf extract (MOLE) against cadmium toxicity was investigated in the model eukaryote Saccharomyces cerevisiae. The results showed that this extract exhibited a protective effect against oxidative stress induced by cadmium and H2O2 through the reduction of intracellular reactive oxygen species. Interestingly, not only the co-exposure of soluble MOLE with cadmium but also pretreatment of this extract prior to cadmium exposure significantly reduced the cadmium uptake through an inhibition of Fet4p, a low-affinity iron(II) transporter. In addition, the supplementation of soluble MOLE significantly reduced intracellular iron accumulation in a Fet4p-independent manner. Our findings suggest the potential use of soluble extract from M. oleifera leaves as a dietary supplement for protection against cadmium accumulation and oxidative stress. PMID:26675819

  11. Soluble Moringa oleifera leaf extract reduces intracellular cadmium accumulation and oxidative stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kerdsomboon, Kittikhun; Tatip, Supinda; Kosasih, Sattawat; Auesukaree, Choowong

    2016-05-01

    Moringa oleifera leaves are a well-known source of antioxidants and traditionally used for medicinal applications. In the present study, the protective action of soluble M. oleifera leaf extract (MOLE) against cadmium toxicity was investigated in the model eukaryote Saccharomyces cerevisiae. The results showed that this extract exhibited a protective effect against oxidative stress induced by cadmium and H2O2 through the reduction of intracellular reactive oxygen species. Interestingly, not only the co-exposure of soluble MOLE with cadmium but also pretreatment of this extract prior to cadmium exposure significantly reduced the cadmium uptake through an inhibition of Fet4p, a low-affinity iron(II) transporter. In addition, the supplementation of soluble MOLE significantly reduced intracellular iron accumulation in a Fet4p-independent manner. Our findings suggest the potential use of soluble extract from M. oleifera leaves as a dietary supplement for protection against cadmium accumulation and oxidative stress.

  12. The Impact of Polyvinylpyrrolidone on Properties of Cadmium Oxide Semiconductor Nanoparticles Manufactured by Heat Treatment Technique

    Directory of Open Access Journals (Sweden)

    Naif Mohammed Al-Hada

    2016-04-01

    Full Text Available Cadmium oxide semiconductor nanoparticles were produced using a water based mixture, incorporating cadmium nitrates, polyvinyl pyrrolidone (PVP, and calcination temperature. An X-ray diffraction (XRD evaluation was conducted to determine the degree of crystallization of the semiconductor nanoparticles. In addition, scanning electron microscopy (SEM was conducted to identify the morphological features of the nanoparticles. The typical particle sizes and particle dispersal were analyzed via the use of transmission electron microscopy (TEM. The findings provided further support for the XRD outcomes. To determine the composition phase, Fourier transform infrared spectroscopy (FT-IR was conducted, as it indicated the existence of not only metal oxide ionic band in the selection of samples, but also the efficient removal of organic compounds following calcinations. The optical characteristics were demonstrated, so as to analyze the energy band gap via the use of a UV–Vis spectrophotometer. A reduced particle size resulted in diminution of the intensity of photoluminescence, was demonstrated by PL spectra. Plus, the magnetic characteristics were examined using an electron spin resonance (ESR spectroscopy, which affirmed the existence of unpaired electrons.

  13. Oxidative stress and DNA damages induced by cadmium accumulation

    Institute of Scientific and Technical Information of China (English)

    LIN Ai-jun; ZHANG Xu-hong; CHEN Mei-mei; CAO Qing

    2007-01-01

    Experimental evidence shows that cadmium (Cd) could induce oxidative stress and then causes DNA damage in animal cells, however, whether such effect exists in plants is still unclear. In the present study, Vicia faba plants was exposed to 5 and 10 mg/L Cd for 4 d to investigate the distribution of Cd in plant, the metal effects on the cell lipids, antioxidative enzymes and DNA damages in leaves. Cd induced an increase in Cd concentrations in plants. An enhanced level of lipid peroxidation in leaves and an enhanced concentration of H2O2 in root tissues suggested that Cd caused oxidative stress in Vicia faba. Compared with control, Cd-induced enhancement in superoxide dismutase activity was significant at 5 mg/L than at 10 mg/kg in leaves, by contrast, catalase and peroxidaseactivities were significantly suppressed by Cd addition. DNA damage was detected by neutral/neutral, alkaline/neutral and alkaline/alkaline Comet assay. Increased levels of DNA damages induced by Cd occurred with reference to oxidative stress in leaves, therefore, oxidative stress induced by Cd accumulation in plants contributed to DNA damages and was possibly an important mechanism of Cd-phytotoxicity in Vicia faba plants.

  14. Protective Effect of Cleistocalyx nervosum var. paniala Fruit Extract against Oxidative Renal Damage Caused by Cadmium

    Directory of Open Access Journals (Sweden)

    Warut Poontawee

    2016-01-01

    Full Text Available Cadmium nephrotoxicity is a serious environmental health problem as it will eventually end up with end stage renal disease. The pathobiochemical mechanism of this toxic heavy metal is related to oxidative stress. This study investigated whether Cleistocalyx nervosum var. paniala fruit extract (CNFE could protect the kidney against oxidative injury caused by cadmium. Initial analysis of the extract revealed antioxidant abilities and high levels of polyphenols, particularly catechin. Its potential renal benefits was further explored in rats treated with vehicle, CNFE, cadmium (2 mg/kg, and cadmium plus CNFE (0.5, 1, 2 g/kg for four weeks. Oxidative renal injury was developed after cadmium exposure as evidenced by blood urea nitrogen and creatinine retention, glomerular filtration reduction, renal structural damage, together with increased nitric oxide and malondialdehyde, but decreased antioxidant thiols, superoxide dismutase, and catalase in renal tissues. Cadmium-induced nephrotoxicity was diminished in rats supplemented with CNFE, particularly at the doses of 1 and 2 g/kg. It is concluded that CNFE is able to protect against the progression of cadmium nephrotoxicity, mostly via its antioxidant power. The results also point towards a promising role for this naturally-occurring antioxidant to combat other human disorders elicited by disruption of redox homeostasis.

  15. Role of oxidative stress in cadmium toxicity and carcinogenesis

    International Nuclear Information System (INIS)

    Cadmium (Cd) is a toxic metal, targeting the lung, liver, kidney, and testes following acute intoxication, and causing nephrotoxicity, immunotoxicity, osteotoxicity and tumors after prolonged exposures. Reactive oxygen species (ROS) are often implicated in Cd toxicology. This minireview focused on direct evidence for the generation of free radicals in intact animals following acute Cd overload and discussed the association of ROS in chronic Cd toxicity and carcinogenesis. Cd-generated superoxide anion, hydrogen peroxide, and hydroxyl radicals in vivo have been detected by the electron spin resonance spectra, which are often accompanied by activation of redox sensitive transcription factors (e.g., NF-κB, AP-1 and Nrf2) and alteration of ROS-related gene expression. It is generally agreed upon that oxidative stress plays important roles in acute Cd poisoning. However, following long-term Cd exposure at environmentally-relevant low levels, direct evidence for oxidative stress is often obscure. Alterations in ROS-related gene expression during chronic exposures are also less significant compared to acute Cd poisoning. This is probably due to induced adaptation mechanisms (e.g., metallothionein and glutathione) following chronic Cd exposures, which in turn diminish Cd-induced oxidative stress. In chronic Cd-transformed cells, less ROS signals are detected with fluorescence probes. Acquired apoptotic tolerance renders damaged cells to proliferate with inherent oxidative DNA lesions, potentially leading to tumorigenesis. Thus, ROS are generated following acute Cd overload and play important roles in tissue damage. Adaptation to chronic Cd exposure reduces ROS production, but acquired Cd tolerance with aberrant gene expression plays important roles in chronic Cd toxicity and carcinogenesis.

  16. Cadmium Chloride Induces DNA Damage and Apoptosis of Human Liver Carcinoma Cells via Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Anthony Skipper

    2016-01-01

    Full Text Available Cadmium is a heavy metal that has been shown to cause its toxicity in humans and animals. Many documented studies have shown that cadmium produces various genotoxic effects such as DNA damage and chromosomal aberrations. Ailments such as bone disease, renal damage, and several forms of cancer are attributed to overexposure to cadmium.  Although there have been numerous studies examining the effects of cadmium in animal models and a few case studies involving communities where cadmium contamination has occurred, its molecular mechanisms of action are not fully elucidated. In this research, we hypothesized that oxidative stress plays a key role in cadmium chloride-induced toxicity, DNA damage, and apoptosis of human liver carcinoma (HepG2 cells. To test our hypothesis, cell viability was determined by MTT assay. Lipid hydroperoxide content stress was estimated by lipid peroxidation assay. Genotoxic damage was tested by the means of alkaline single cell gel electrophoresis (Comet assay. Cell apoptosis was measured by flow cytometry assessment (Annexin-V/PI assay. The result of MTT assay indicated that cadmium chloride induces toxicity to HepG2 cells in a concentration-dependent manner, showing a 48 hr-LD50 of 3.6 µg/mL. Data generated from lipid peroxidation assay resulted in a significant (p < 0.05 increase of hydroperoxide production, specifically at the highest concentration tested. Data obtained from the Comet assay indicated that cadmium chloride causes DNA damage in HepG2 cells in a concentration-dependent manner. A strong concentration-response relationship (p < 0.05 was recorded between annexin V positive cells and cadmium chloride exposure. In summary, these in vitro studies provide clear evidence that cadmium chloride induces oxidative stress, DNA damage, and programmed cell death in human liver carcinoma (HepG2 cells.

  17. Sulfur dioxide effect on cadmium and zinc oxide interaction with chlorine

    International Nuclear Information System (INIS)

    Comparison of electrophysical properties of cadmium and zinc oxides with kinetic regularities of their interaction with Cl2 and SO2 was conducted. It is shown that SO2 presence in gas phase leads to retardation of chlorination of both oxides. In the case of CdO the effect of SO2 is manifested more clearly

  18. Cadmium-induced oxidative stress in potato tuber

    Directory of Open Access Journals (Sweden)

    Andrzej Stroiński

    2014-02-01

    Full Text Available Short-term treatment of tuber discs of potato (Solanum tuberosum L. with cadmium chloride elevated the concentration of active oxygen species (.O-2, H202 and activated the antioxidative system. Two cultivars, Bintje and Bzura, susceptible and tolerant, respectively, to cadmium were examined. In more tolerant, control tissues the activity of ascorbic acid peroxidase (AAP and catalase (CAT was higher than in the sensitive ones. During first hours of stress, the inhibition of superoxide dismutase (SOD, CAT and AAP was observed and it comes from inactivation of enzymes by cadmium ions. A subsequent activity increase of the enzymes aroused earlier in tolerant tissues. It seems therefore, that tolerant tissues possess a more efficient antioxidative system.

  19. Oxidative stress in duckweed (Lemna minor L.) caused by short-term cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Razinger, Jaka [Department for Environmental Technologies and Biomonitoring, Institute of Physical Biology, Veliko Mlacevo 59, SI-1290 Grosuplje (Slovenia)], E-mail: jaka@ifb.si; Dermastia, Marina [National Institute of Biology, Vecna pot 111, p.p. 141, SI-1001 Ljubljana (Slovenia); Biotechnical Faculty, Department of Biology, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana (Slovenia); Koce, Jasna Dolenc [Biotechnical Faculty, Department of Biology, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana (Slovenia); Zrimec, Alexis [Department for Environmental Technologies and Biomonitoring, Institute of Physical Biology, Veliko Mlacevo 59, SI-1290 Grosuplje (Slovenia)

    2008-06-15

    The mechanisms of plant defence against cadmium toxicity have been studied by short-term exposure of Lemna minor L. (common duckweed) to concentrations of CdCl{sub 2} ranging from 0 to 500 {mu}M. High accumulation of cadmium was observed (12,320 {+-} 2155 {mu}g g{sup -1} at 500 {mu}M CdCl{sub 2}), which caused a gradual decrease of plant growth, increased lipid peroxidation, and weakened the entire antioxidative defence. Total glutathione concentration decreased significantly; however, the concentration of oxidized glutathione remained stable. The responses of four antioxidant enzymes showed that catalase was the most inhibited after CdCl{sub 2} exposure, ascorbate peroxidase and guaiacol peroxidase moderately, and glutathione reductase least. The total antioxidative potential revealed an induced antioxidative network at 0.1 {mu}M CdCl{sub 2} (137 {+-} 13.2% of the control) and its reduction to only 47.4 {+-} 4.0% of the control at higher cadmium concentrations. The possible application of the examined biomarkers in ecotoxicological research is discussed. - The increase of total antioxidative potential at low cadmium concentration is one of the mechanisms that helps duckweed to cope with cadmium-induced oxidative stress.

  20. Comparison of antibacterial activities of cadmium oxide nanoparticles against Pseudomonas Aeruginosa and Staphylococcus Aureus bacteria

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    Bahareh Salehi

    2015-01-01

    Conclusion: This study showed that antibacterial effects of cadmium oxide nanoparticles on positive gram bacteria are stronger than negative gram bacteria and antibacterial effects of cdo nanoparticles against both bacteria, but Staphylococcus aureus bacteria were more sensitive to nanoparticles as compared to Pseudomonas aeruginosa.

  1. Scandium-doped zinc cadmium oxide as a new stable n-type oxide thermoelectric material

    DEFF Research Database (Denmark)

    Han, Li; Christensen, Dennis Valbjørn; Bhowmik, Arghya;

    2016-01-01

    the thermal conductivity by up to 7-fold at room temperature. By carefully selecting the Sc-dopant concentrations, a high power factor of 7.1 × 10−4 W m−1 K−2 at 1173 K could be obtained. Therefore, the highest ZT ∼ 0.3 at 1173 K was achieved for the Zn0.9Cd0.1Sc0.01O1.015 sample, and it has so far one......Scandium-doped zinc cadmium oxide (Sc-doped ZnCdO) is proposed as a new n-type oxide thermoelectric material. The material is sintered in air to maintain the oxygen stoichiometry and avoid instability issues. The successful alloying of CdO with ZnO at a molar ratio of 1 : 9 significantly reduced...... is a good candidate for improving the overall conversion efficiencies in oxide thermoelectric modules. Meanwhile, Sc-doped ZnCdO is robust in air at high temperatures, whereas other n-type materials, such as Al-doped ZnO, will experience rapid degradation of their electrical conductivity and ZT....

  2. Single crystal EPR study of VO(II)-doped cadmium potassium phosphate hexahydrate: A substitutional incorporation

    Indian Academy of Sciences (India)

    I Sougandi; T M Rajendiran; R Venkatesan; P Sambasiva Rao

    2002-10-01

    Single crystal EPR studies of VO(II)-doped cadmium potassium phosphate hexahydrate (CPPH) have been carried out at room temperature. The angular variation spectra in the three orthogonal planes indicate that the paramagnetic impurity has entered the lattice only substitutionally in place of Cd(II). Spin Hamiltonian parameters have been obtained from single crystal data. Powder spectra show a set of eight parallel and perpendicular features indicating the presence of only one site. The admixture coefficients have been calculated from the data, which agree well with the literature values.

  3. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

    International Nuclear Information System (INIS)

    Highlights: ► Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. ► Cd can result in oxidative stress in the frog testes. ► Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. ► Cd can cause apoptosis in the testes of male R. limnocharis. ► Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose–effect relationship. Moreover, the same dosages of Cd2+ solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5–7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a scientific basis accounting for the global population decline in amphibian species.

  4. Investigation of the influence of cadmium processing on zinc gallium oxide:manganese thin films for photoluminescent and thin film electroluminescent applications

    Science.gov (United States)

    Flynn, Michael John

    concentration left by the sublimed material, which aided the incorporation and activation of the manganese. The cadmium in the sputtering targets also impacted the crystal structure of the films. Films from cadmium free targets exhibited a strong (111) x-ray diffraction peak, while those from cadmium processed targets more closely resembled the powder structure. The optimum thin film electroluminescent performance was obtained for films sputtered from targets processed with between 5% and 15% cadmium substituted for zinc. This was the result of improved diffusion during the anneals, due to the sublimation of cadmium oxide and the resulting large vacancy concentration. The best performance was obtained for films annealed at between 875°C and 900°C for 6--12 hours. These films exhibited both the maximum luminance (55 cd/m2 at 60 Hz) and the lowest transferred charge (˜20 muC/cm2). This combined for a peak efficiency of 0.5 lm/W at 60 Hz). Beyond 12 hours at 900°C or temperatures higher than this, EL performance degraded due to the decomposition of the thin film. It was concluded that the luminescent performance of this material is strongly influenced by the loss of cadmium during processing. The enhanced diffusion afforded by the cadmium sublimation results in improved EL performance at annealing temperature lower that that of pure zinc gallate.

  5. Cadmium induced oxidative stress in kidney epithelia cells

    DEFF Research Database (Denmark)

    Bjerregaard, Henning F.

    2007-01-01

    Cadmium (Cd) is an important industrial and environmental pollutant. In humans exposed to Cd via oral and/or pulmonary routes, the kidney is by far the primary organ affected adversely by Cd. It have been estimated that 7% of the human population may develop renal dysfunction from Cd exposure...... of generation of ROS in this pathway remains unclear.     The aim of the present study was to monitor, in real time, the rates of ROS generation to be able to directly determine their production dynamics in living cells in response to drugs. Initial studies were planed in to use 2,7-dichlorofluorescein...

  6. Stress response to cadmium and manganese in Paracentrotus lividus developing embryos is mediated by nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Migliaccio, Oriana; Castellano, Immacolata [Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples (Italy); Romano, Giovanna [Laboratory of Functional and Evolutionary Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples (Italy); Palumbo, Anna, E-mail: anna.palumbo@szn.it [Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples (Italy)

    2014-11-15

    Highlights: • NO is produced in sea urchin embryos in response to cadmium and manganese. • Cadmium and manganese affect the expression of specific genes. • NO levels regulate directly or indirectly the expression of some metal-induced genes. • NO is proposed as a sensor of different stress agents in sea urchin embryos. - Abstract: Increasing concentrations of contaminants, often resulting from anthropogenic activities, have been reported to occur in the marine environment and affect marine organisms. Among these, the metal ions cadmium and manganese have been shown to induce developmental delay and abnormalities, mainly reflecting skeleton elongation perturbation, in the sea urchin Paracentrotus lividus, an established model for toxicological studies. Here, we provide evidence that the physiological messenger nitric oxide (NO), formed by L-arginine oxidation by NO synthase (NOS), mediates the stress response induced by cadmium and manganese in sea urchins. When NO levels were lowered by inhibiting NOS, the proportion of abnormal plutei increased. Quantitative expression of a panel of 19 genes involved in stress response, skeletogenesis, detoxification and multidrug efflux processes was followed at different developmental stages and under different conditions: metals alone, metals in the presence of NOS inhibitor, NO donor and NOS inhibitor alone. These data allowed the identification of different classes of genes whose metal-induced transcriptional expression was directly or indirectly mediated by NO. These results open new perspectives on the role of NO as a sensor of different stress agents in sea urchin developing embryos.

  7. Thermodynamics and kinetics of cadmium adsorption onto oxidized granular activated carbon

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cadmium sorption behavior of granular activated carbon oxidized with nitric acid was systematically studied by sets of the equilibrium and time-based experiments under various conditions. The cadmium adsorption capacity of oxidized granular activated carbon enlarged with an increase in pH, and reduced with an increase in ionic strength. Experimental data were evaluated to find out kinetic characteristics. Adsorption processes were found to follow pseudo-second order rate equation. Adsorption isotherms correlate well with the Langmuir isotherm model and the maximum sorption capacity of cadmium evaluated is 51.02 μmol/g. Thermodynamic parameters were calculated based on Van't Hoff equation. Equilibrium constant Kd was evaluated from Freundlich isotherm model constants, Langmuir isotherm model constants and isotherms, respectively. The average change of standard adsorption heat ΔHo is -25.29 kJ/mol. Negative ΔHo and ΔGo values indicate the adsorption process for cadmium onto the studied activated carbon is exothermic and spontaneous. The standard entropy ΔSo is also negative, which suggests a decrease in the freedom of the system.

  8. Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II) Ions

    OpenAIRE

    Ibrahim, I.; Lim, H. N; N. M. Huang; Pandikumar, A

    2016-01-01

    A photoelectrochemical (PEC) sensor with excellent sensitivity and detection toward copper (II) ions (Cu2+) was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO) nanocomposite on an indium tin oxide (ITO) surface, with triethanolamine (TEA) used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD) method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively....

  9. Transcriptional responses indicate attenuated oxidative stress in the springtail Folsomia candida exposed to mixtures of cadmium and phenanthrene.

    Science.gov (United States)

    de Boer, Muriel E; Ellers, Jacintha; van Gestel, Cornelis A M; den Dunnen, Johan T; van Straalen, Nico M; Roelofs, Dick

    2013-05-01

    Since the 'omics revolution', the assessment of toxic chemical mixtures has incorporated approaches where phenotypic endpoints are connected to a mechanistic understanding of toxicity. In this study we determined the effect of binary mixtures of cadmium and phenanthrene on the reproduction of Folsomia candida and investigated the cellular mechanisms underlying this response. Mixture toxicity modeling showed an antagonistic deviation from concentration addition for reproduction effects of the mixtures. Subsequent transcriptional response analysis was done using five mixtures at the modeled 50 % effect level for reproduction. The transcription profiles of 86 high throughput RT-qPCR assays were studied by means of partial least squares regression analysis. The first and second principal components (PCs) were correlated with global responses to cadmium and phenanthrene, while correlations with the mixture treatments were found in the higher PCs. Specifically associated with the mixture treatments were a biotransformation phase II gene, four mitochondrial related genes and a gene involved in the biosynthesis of antioxidant selenoproteins. Membrane integrity related gene inductions were correlated with the single phenanthrene treatment but not with the mixtures. Immune and inflammatory response assays did not correlate with any of the mixtures. These results suggest moderated oxidative stress, a higher mitochondrial maintenance and less compromised membrane function in the mixture exposed samples compared to the separate cadmium or phenanthrene exposures. The antagonism found for inhibition of reproduction may partially originate from these differences. Mechanistic studies on mixture toxicity can ultimately aid risk assessment by defining relevant toxicity pathways in organisms exposed to real-world mixture exposures present in the field. PMID:23483327

  10. Sputtered cadmium oxide as a surface pretreatment for graphite solid lubricant films

    Science.gov (United States)

    Fusaro, R. L.

    1986-01-01

    Sputtered films of cadmium oxide were applied to sand blasted AISI 440C HT stainless steel disks as a surface pretreatment for the application of rubbed graphite films. Mixtures of cadmium oxide and graphite were applied to the nonpretreated sandblasted metal and evaluated. The results were compared to graphite films applied to other commercially available surface pretreatments. It is found that sputtered CdO pretreated surfaces increase the endurance lives of the graphite films and decrease the counterface steady state wear rate of the pins almost an order of magnitude compared to commercially available pretreatments. The CdO additions in general improved the tribological properties of graphite. The greatest benefit occurred when it was applied to the substrate rather than mixing it with the graphite and that sputtered films of CdO perform much better than rubbed CdO films.

  11. Sputtered cadmium oxide as a surface pretreatment for graphite solid-lubricant films

    Science.gov (United States)

    Fusaro, Robert L.

    1987-01-01

    Sputtered films of cadmium oxide were applied to sand blasted AISI 440C HT stainless steel disks as a surface pretreatment for the application of rubbed graphite films. Mixtures of cadmium oxide and graphite were applied to the nonpretreated sandblasted metal and evaluated. The results were compared to graphite films applied to other commercially available surface pretreatments. It is found that sputtered CdO pretreated surfaces increase the endurance lives of the graphite films and decrease the counterface steady state wear rate of the pins almost an order of magnitude compared to commercially available pretreatments. The CdO additions in general improved the tribological properties of graphite. The greatest benefit occurred when it was applied to the substrate rather than mixing it with the graphite and that sputtered films of CdO perform much better than rubbed CdO films.

  12. Comparison of antibacterial activities of cadmium oxide nanoparticles against Pseudomonas Aeruginosa and Staphylococcus Aureus bacteria

    OpenAIRE

    Bahareh Salehi; Esmaeil Mortaz; Payam Tabarsi

    2015-01-01

    Background: Inorganic antibacterial factors have bacterial resistance and high thermal stability. Inorganic nanomaterials which have new structures with biological, chemical and physical properties have been made since their applications due to their nano size. In this study, the antibacterial effect of cadmium oxide nanoparticles on Staphylococcus aureus and Pseudomonas aeruginosa bacteria was investigated. Materials and Methods: The different concentrations (10 μg/ml, 15 μg/ml and 20 μg...

  13. Investigation of antibacterial effect of Cadmium Oxide nanoparticles on Staphylococcus Aureus bacteria

    OpenAIRE

    Salehi, Bahareh; Mehrabian, Sedigheh; Ahmadi, Mehdi

    2014-01-01

    Background Inorganic antibacterial factors provide high bacterial resistance and thermal stability. Inorganic nanomaterial consists of modern formulation, biological, chemical, and physical properties produced on the basis of their function and influenced by their nano scales, the reason for which they have become very popular. The antibacterial effect of Cadmium Oxide Nanoparticles on Staphylococcus Aureus has been studied for the first time in this research because of their resistance to an...

  14. Purification of cadmium by selective volatilization in vacuum in presence of oxide phase on its melt

    Indian Academy of Sciences (India)

    N R Munirathnam; K Srinivasa Rao; T L Prakash

    2012-04-01

    Purification of cadmium in the presence of a thin (∼0.001 mm) oxide layer on the surface of the molten metal was carried out using a simple system designed and fabricated locally. The analytical results revealed that the distillation through oxide layer gave better separation for Co, Ni, Cu, Zn, Ag, Sn, Hg and Tl, when compared to the distillation without oxide layer. This was attributed due to the impurity metal oxide phases formation on the surface of the molten metal. The influence of oxygen flow time on the distillation rate of cadmium was established. There was no excess oxygen (O) retained in the distillate after two consecutive vacuum distillations through oxide route. The experiments were conducted at the level of nearly 1.5 kg a batch to study the impurities behaviour due to upscaling. The detailed chemical analysis of 58 impurity elements in Cd in presence and absence of oxide layer was carried out by glow discharge mass spectrometry (GDMS).

  15. Band gap engineering of indium zinc oxide by nitrogen incorporation

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, J.J., E-mail: jjosila@hotmail.com [Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad esq. Paseo la Bufa, Fracc. Progreso, C.P. 98060 Zacatecas (Mexico); Doctorado Institucional de Ingeniería y Ciencia de Materiales, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava, Zona Universitaria, C.P. 78270 San Luis Potosí (Mexico); Aguilar-Frutis, M.A.; Alarcón, G. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada del Instituto Politécnico Nacional, Unidad Legaría, Calz. Legaría No. 694, Col. Irrigación, C.P. 11500 México D.F. (Mexico); Falcony, C. [Departamento de Física, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional campus Zacatenco, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 México D.F. (Mexico); and others

    2014-09-15

    Highlights: • IZON thin films were deposited by RF reactive sputtering at room temperature. • The effects of nitrogen on physical properties of IZO were analyzed. • Optical properties of IZON were studied by SE and UV–vis spectroscopy. • Adachi and classical parameters were quantitative and qualitatively congruent. • Nitrogen induces a gradual narrowing band gap from 3.5 to 2.5 eV on IZON films. - Abstract: The effects of nitrogen incorporation in indium zinc oxide films, as grown by RF reactive magnetron sputtering, on the structural, electrical and optical properties were studied. It was determined that the variation of the N{sub 2}/Ar ratio, in the reactive gas flux, was directly proportional to the nitrogen percentage measured in the sample, and the incorporated nitrogen, which substituted oxygen in the films induces changes in the band gap of the films. This phenomenon was observed by measurement of absorption and transmission spectroscopy in conjunction with spectral ellipsometry. To fit the ellipsometry spectra, the classical and Adachi dispersion models were used. The obtained optical parameters presented notable changes related to the increment of the nitrogen in the film. The band gap narrowed from 3.5 to 2.5 eV as the N{sub 2}/Ar ratio was increased. The lowest resistivity obtained for these films was 3.8 × 10{sup −4} Ω cm with a carrier concentration of 5.1 × 10{sup 20} cm{sup −3}.

  16. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China); Jia Xiuying, E-mail: hznujiaxiuying@126.com [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. Black-Right-Pointing-Pointer Cd can result in oxidative stress in the frog testes. Black-Right-Pointing-Pointer Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. Black-Right-Pointing-Pointer Cd can cause apoptosis in the testes of male R. limnocharis. Black-Right-Pointing-Pointer Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose-effect relationship. Moreover, the same dosages of Cd{sup 2+} solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5-7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a

  17. Incorporation of sulfide ions into the cadmium(II) thiolate cluster of Cicer arietinum metallothionein2.

    Science.gov (United States)

    Wan, Xiaoqiong; Freisinger, Eva

    2013-01-18

    The plant metallothionein2 from Cicer arietinum (chickpea), cic-MT2, is known to coordinate five divalent metal ions such as Zn(II) or Cd(II), which are arranged in a single metal thiolate cluster. When the Zn(II) form of the protein is titrated with Cd(II) ions in the presence of sulfide ions, an increased Cd(II) binding capacity and concomitant incorporation of sulfide ions into the cluster are observed. The exact stoichiometry of this novel cluster, its spectroscopic properties, and the significantly increased pH stability are analyzed with different techniques, including UV and circular dichroism spectroscopy and colorimetric assays. Limited proteolytic digestion provides information about the spacial arrangement of the cluster within the protein. Increasing the Cd(II) scavenging properties of a metallothionein by additionally recruiting sulfide ions might be an economic and very efficient detoxification strategy for plants.

  18. Transformation of cadmium hydroxide to cadmium oxide thin films synthesized by SILAR deposition process: Role of varying deposition cycles

    Directory of Open Access Journals (Sweden)

    A.C. Nwanya

    2016-06-01

    Full Text Available Successive Ionic Layer Adsorption and Reaction (SILAR was used to deposit nanocrystalline cadmium oxide (CdO thin films on microscopic glass substrates for various cycles (40–120. This is based on alternate dipping of the substrate in CdCl2 solution made alkaline (pH ∼12 with NaOH, rinsing with distilled water, followed by air treatment with air dryer and annealing at 300 °C for 1 h in air. The prepared films were characterized by X-ray diffraction (XRD, UV–Visible Spectrophotomer (UV–Vis and Scanning Electron Microscopy (SEM. The 80th cycle was observed to be the saturation stage for this reaction. The XRD results confirmed the films to be CdO with some Cd(OH2 phase at higher deposition cycles. The films were polycrystalline in nature having high orientation along (111 and (200 planes. As the number of cycles increases the calculated average crystallite sizes increase gradually up till the 80th cycle after which a gradual decrease in the crystallite size was observed with increasing number of cycles. The films’ transmittance in the visible and near infrared region decreased as the number of cycles increased and ranged between 25 and 80%. This work shows the feasibility of using simple SILAR method at room temperature to obtain Cd(OH2 films which are transformed to CdO thin films after annealing.

  19. Reversal of Cadmium-induced Oxidative Stress in Chicken by Herbal Adaptogens Withania Somnifera and Ocimum Sanctum

    OpenAIRE

    K Bharavi; Reddy, A. Gopala; G S Rao; Reddy, A. Rajasekhara; Rao, S. V. Rama

    2010-01-01

    The present study was carried out to evaluate the herbal adaptogens Withania somnifera and Ocimum sanctum on cadmium-induced oxidative toxicity in broiler chicken. Cadmium administration at the rate of 100 ppm orally along with feed up to 28 days produced peroxidative damage, as indicated by increase in TBARS, reduction in glutathione (GSH) concentration in liver and kidney, and increase in catalase (CAT) and superoxide dismutase (SOD) of erythrocytes. Herbal adaptogens Withania somnifera roo...

  20. Nitric oxide-activated hydrogen sulfide is essential for cadmium stress response in bermudagrass (Cynodon dactylon (L). Pers.).

    Science.gov (United States)

    Shi, Haitao; Ye, Tiantian; Chan, Zhulong

    2014-01-01

    Nitric oxide (NO) and hydrogen sulfide (H2S) are important gaseous molecules, serving as important secondary messengers in plant response to various biotic and abiotic stresses. However, the interaction between NO and H2S in plant stress response was largely unclear. In this study, endogenous NO and H2S were evidently induced by cadmium stress treatment in bermudagrass, and exogenous applications of NO donor (sodium nitroprusside, SNP) or H2S donor (sodium hydrosulfide, NaHS) conferred improved cadmium stress tolerance. Additionally, SNP and NaHS treatments alleviated cadmium stress-triggered plant growth inhibition, cell damage and reactive oxygen species (ROS) burst, partly via modulating enzymatic and non-enzymatic antioxidants. Moreover, SNP and NaHS treatments also induced the productions of both NO and H2S in the presence of Cd. Interestingly, combined treatments with inhibitors and scavengers of NO and H2S under cadmium stress condition showed that NO signal could be blocked by both NO and H2S inhibitors and scavengers, while H2S signal was specifically blocked by H2S inhibitors and scavengers, indicating that NO-activated H2S was essential for cadmium stress response. Taken together, we assigned the protective roles of endogenous and exogenous NO and H2S in bermudagrass response to cadmium stress, and speculated that NO-activated H2S might be essential for cadmium stress response in bermudagrass.

  1. Improved Sensitization of Zinc Oxide Nanorods by Cadmium Telluride Quantum Dots through Charge Induced Hydrophilic Surface Generation

    Directory of Open Access Journals (Sweden)

    Karthik Laxman

    2014-01-01

    Full Text Available This paper reports on UV-mediated enhancement in the sensitization of semiconductor quantum dots (QDs on zinc oxide (ZnO nanorods, improving the charge transfer efficiency across the QD-ZnO interface. The improvement was primarily due to the reduction in the interfacial resistance achieved via the incorporation of UV light induced surface defects on zinc oxide nanorods. The photoinduced defects were characterized by XPS, FTIR, and water contact angle measurements, which demonstrated an increase in the surface defects (oxygen vacancies in the ZnO crystal, leading to an increase in the active sites available for the QD attachment. As a proof of concept, a model cadmium telluride (CdTe QD solar cell was fabricated using the defect engineered ZnO photoelectrodes, which showed ∼10% increase in photovoltage and ∼66% improvement in the photocurrent compared to the defect-free photoelectrodes. The improvement in the photocurrent was mainly attributed to the enhancement in the charge transfer efficiency across the defect rich QD-ZnO interface, which was indicated by the higher quenching of the CdTe QD photoluminescence upon sensitization.

  2. Boron-doped cadmium oxide composite structures and their electrochemical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, B.J., E-mail: bjlokhande@yahoo.com [Lab of Smart Mtrls Supercapacitive and Energy Studies, School of Physical Sciences, Solapur University, Solapur 413255, Maharashtra (India); Ambare, R.C. [Lab of Smart Mtrls Supercapacitive and Energy Studies, School of Physical Sciences, Solapur University, Solapur 413255, Maharashtra (India); Mane, R.S. [School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606 (India); Bharadwaj, S.R. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2013-08-01

    Graphical abstract: Conducting nano-fibrous 3% boron doped cadmium oxide thin films were prepared by SILAR and its super capacitive properties were studied. - Highlights: • Samples are of nanofibrous nature. • All samples shows pseudocapacitive behavior. • 3% B doped CdO shows good specific capacitance. • 3% B doped CdO shows maximum 74.93% efficiency at 14 mA/cm{sup 2}. • 3% B doped CdO shows 0.8 Ω internal resistance. - Abstract: Boron-doped and undoped cadmium oxide composite nanostructures in thin film form were prepared onto stainless steel substrates by a successive ionic layer adsorption and reaction method using aqueous solutions of cadmium nitrate, boric acid and 1% H{sub 2}O{sub 2}. As-deposited films were annealed at 623 K for 1 h. The X-ray diffraction study shows crystalline behavior for both doped and undoped films with a porous topography and nano-wires type architecture, as observed in SEM image. Wettability test confirms the hydrophilic surface with 58° contact angle value. Estimated band gap energy is around 1.9 eV. Electrochemical behavior of the deposited films is attempted in 1 M KOH electrolyte using cyclic voltammetry (CV), electrochemical impedance spectroscopy and galvanostatic charge–discharge tests. Maximum values of the specific capacitance, specific energy and specific power obtained for 3% B doped CdO film at 2 mV/s scan rate are 20.05 F/g, 1.22 Wh/kg and 3.25 kW/kg, respectively.

  3. Increased Oxidative DNA Damage in Placenta Contributes to Cadmium-Induced Preeclamptic Conditions in Rat.

    Science.gov (United States)

    Zhang, Xiaojie; Xu, Zhangye; Lin, Feng; Wang, Fan; Ye, Duyun; Huang, Yinping

    2016-03-01

    To explore the possible mechanisms of cadmium (Cd)-induced preeclamptic conditions in rats. In the present study, we introduced the in vivo model of preeclampsia by giving intraperitoneal injections of cadmium chloride (CdCl2) to pregnant rats from gestational day (GD) 4 to 19. Maternal body weights were recorded on GD 0, 14, and 20, while their systolic blood pressures (SBPs) monitored on GD 3, 11, and 18. On GD 20, rats were sacrificed and the specimens were collected. The morphological changes of placenta and kidney tissues of pregnant rats were examined by hematoxylin and eosin staining assay. Blood Cd level was detected by inductively coupled plasma mass spectrometry. Total antioxidant capacity (TAC) was evaluated using FRAP method and total nitrite (NOx) was detected with Griess reagent. Antioxidative factors and DNA damage/repair biomarkers were measured by real-time qPCR, western blot or immunohistochemistry study. The current results showed that CdCl2-treated pregnant rats developed preeclampsia (PE)-like manifestations, such as hypertension, albuminuria, with decreased TAC and increased blood Cd level, and pro-oxidative/antioxidative or DNA damage/repair biomarkers. Our study demonstrated that increased oxidative DNA damage in placenta could contribute to Cd-induced preeclamptic conditions in rat. PMID:26194818

  4. Comparative study of natural antioxidants - curcumin, resveratrol and melatonin - in cadmium-induced oxidative damage in mice

    International Nuclear Information System (INIS)

    The present study was designed to examine the antioxidative effect of curcumin, resveratrol and melatonin pre-treatment on cadmium-induced oxidative damage and cadmium distribution in an experimental model in mice. Male CD mice were treated once daily for 3 days with curcumin (50 mg/kg b.w., p.o.), resveratrol (20 mg/kg b.w., p.o.) or melatonin (12 mg/kg, p.o.), dispersed in 0.5% methylcellulose. One hour after the last dose of antioxidants cadmium chloride was administered (7 mg/kg b.w., s.c.) to pre-treated animals and control animals receiving methylcellulose. At 24th h after Cd administration the lipid peroxidation (LP - expressed as malondialdehyde production), reduced glutathione (GSH), catalase (CAT) and glutathione peroxidase (GPx) were estimated in liver homogenates. Cadmium concentration was measured in the liver, kidneys, testes and brain by AAS. Cadmium chloride administration to mice induced hepatic lipid peroxidation (to 133%, p < 0.001), decreased GSH content (to 65%, p < 0.001) and inhibited catalase (to 68%, p < 0.001) and GPx activity (to 60%, p < 0.001) in the liver. Curcumin, resveratrol and melatonin oral pre-treatment completely prevented the Cd-induced lipid peroxidation and Cd-induced inhibition of GPx hepatic activity. Resveratrol was effective against Cd-induced inhibition of catalase activity (p < 0.001). The decrease in hepatic GSH level was not prevented by curcumin, resveratrol or melatonin pre-treatment. In mice treated with antioxidants alone the level of LP, GSH, GPx or CAT was not different from control levels. The pre-treatment with antioxidants did not affect cadmium distribution in the tissues of Cd-intoxicated mice. The results demonstrate that curcumin, resveratrol and melatonin pre-treatment effectively protect against cadmium-induced lipid peroxidation and ameliorate the adverse effect of cadmium on antioxidant status without any reduction in tissue Cd burden

  5. Restorative Effects of Zinc and Selenium on Cadmium-induced Kidney Oxidative Damage in Rats

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To investigate whether cadmium-induced oxidative stress in the kidney is influenced by zinc and selenium. Methods Five groups of rats were maintained: (A) Cd (CdCl2,400 μg@kg-1 day-1 intraperitoneal injection); (B) Cd+Zn (ZnC12, 20mg kg-1.day-1 hypodermic injection); (C) Cd+Se (Na2SeO3, 350 μg.kg-1.day-1 via a stomach tube); (D) Cd+Zn+Se; (E)treated with physiological saline as a sham-handled control. The rats were given treatmenl for a period of 4 weeks. The activities of superoxide dismutase (SOD), glutathione peroxidase (GH-Px), catalase (CAT), and the level of malondialdehyde (MDA) in the kidney tissue were measured to assess the oxidative stress. Urinary lactate dehydrogenase (LDH) activity was used as an indicator of tubular cell damage caused by lipid peroxidation. Results In group C and D, activities of SOD (110.5 ± 5.2, 126.8 ± 7.0; P < 0.05) and GSH-Px (85.7 ± 4.9,94.6 ± 7.3; P < 0.05) were higher than those in group A(84.7 ± 3.3; 56.9 ± 3.8); and in group B, only the activity of GSH-Px (80.0 + 4.3, P < 0.01) increased in comparison with that in group A (56.9 ± 3.8). Significant increase of MDA (P < 0.05) was seen in group B (31.1 ± 4.7) and C (35.0 + 4.1) when compared with control values (17.2 ± 1.8). No difference was found in the level of MDA between group D (18.9 ± 2.6) and control. The activity of LDH in urine of control group (0.06 ± 0.02) was lower than that of group A (0.46 ± 0.19, P<0.05), B (0.10± 0.05, P<0.05) and C (0.14 ± 0.07, P<0.05), and there was no significant change between control (0.06 + 0.02) and group D (0.08 ± 0.02). Conclusion Zinc or selenium could partially alleviate the oxidative stress induced by cadmium in kidney, but administration cadmium in combination with zinc and selenium efficiently protects kidney from cadmiuminduced oxidative damage.

  6. Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    NARCIS (Netherlands)

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.

    2014-01-01

    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  7. Incorporation of oxidized uranium into Fe (hydr)oxides during Fe(II) catalyzed remineralization

    Energy Technology Data Exchange (ETDEWEB)

    Nico, Peter S.; Stewart, Brandy D.; Fendorf, Scott

    2009-07-01

    The form of solid phase U after Fe(II) induced anaerobic remineralization of ferrihydrite in the presence of aqueous and absorbed U(VI) was investigated under both abiotic batch and biotic flow conditions. Experiments were conducted with synthetic ground waters containing 0.168 mM U(VI), 3.8 mM carbonate, and 3.0 mM Ca{sup 2+}. In spite of the high solubility of U(VI) under these conditions, appreciable removal of U(VI) from solution was observed in both the abiotic and biotic systems. The majority of the removed U was determined to be substituted as oxidized U (U(VI) or U(V)) into the octahedral position of the goethite and magnetite formed during ferrihydrite remineralization. It is estimated that between 3% and 6% of octahedral Fe(III) centers in the new Fe minerals were occupied by U(VI). This site specific substitution is distinct from the non-specific U co-precipitation processes in which uranyl compounds, e.g. uranyl hydroxide or carbonate, are entrapped with newly formed Fe oxides. The prevalence of site specific U incorporation under both abiotic and biotic conditions and the fact that the produced solids were shown to be resistant to both extraction (30 mM KHCO{sub 3}) and oxidation (air for 5 days) suggest the potential importance of sequestration in Fe oxides as a stable and immobile form of U in the environment.

  8. Dietary antioxidant and anti-inflammatory intake modifies the effect of cadmium exposure on markers of systemic inflammation and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Colacino, Justin A.; Arthur, Anna E.; Ferguson, Kelly K.; Rozek, Laura S., E-mail: rozekl@umich.edu

    2014-05-01

    Chronic cadmium exposure may cause disease through induction of systemic oxidative stress and inflammation. Factors that mitigate cadmium toxicity and could serve as interventions in exposed populations have not been well characterized. We used data from the 2003–2010 National Health and Nutrition Examination Survey to quantify diet's role in modifying associations between cadmium exposure and oxidative stress and inflammation. We created a composite antioxidant and anti-inflammatory diet score (ADS) by ranking participants by quintile of intake across a panel of 19 nutrients. We identified associations and effect modification between ADS, urinary cadmium, and markers of oxidative stress and inflammation by multiple linear regression. An interquartile range increase in urinary cadmium was associated with a 47.5%, 8.8%, and 3.7% increase in C-reactive protein (CRP), gamma glutamyl transferase (GGT), and alkaline phosphatase (ALP), respectively. An interquartile range increase in ADS was associated with an 7.4%, 3.3%, 5.2%, and 2.5% decrease in CRP, GGT, ALP, and total white blood cell count respectively, and a 3.0% increase in serum bilirubin. ADS significantly attenuated the association between cadmium exposure, CRP and ALP. Dietary interventions may provide a route to reduce the impact of cadmium toxicity on the population level. - Highlights: • Cadmium may cause chronic disease through oxidative stress or inflammation. • We developed a score to quantify dietary antioxidant and anti-inflammatory intake. • Cadmium was associated with markers of oxidative stress and inflammation. • Antioxidant and anti-inflammatory intake mitigated the effects of cadmium exposure. • Dietary interventions may be effective against chronic cadmium toxicity.

  9. Cadmium and mercury cause an oxidative stress-induced endothelial dysfunction.

    Science.gov (United States)

    Wolf, Matthew B; Baynes, John W

    2007-02-01

    We investigated the ability of cadmium and mercury ions to cause endothelial dysfunction in bovine pulmonary artery endothelial cell monolayers. Exposure of monolayers for 48 h to metal concentrations greater than 3-5 microM produced profound cytotoxicity (increased lactate dehydrogenase leakage), a permeability barrier failure, depletion of glutathione and ATP and almost complete inhibition of the activity of key thiol enzymes, glucose-6-phosphate dehydrogenase (G6PDH) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In contrast, metal concentrations less than 1-2 microM induced increases in glutathione and thiol-enzyme activities with minimal changes in LDH leakage, barrier function and ATP content. At shorter incubation times (24 h or less), high concentrations of cadmium caused glutathione induction rather than depletion. Thus, oxidative stress and cytotoxicity induced by lower concentrations of the metal ions stimulate compensatory responses, including increased synthesis of glutathione, which presumably preserved the activity of key thiol enzymes, however these responses were not sustainable at higher metal ion concentrations. We conclude, while high concentrations of heavy metals are cytotoxic, lower concentration induce a compensatory protective response, which may explain threshold effects in metal-ion toxicity.

  10. Revealing a room temperature ferromagnetism in cadmium oxide nanoparticles: An experimental and first-principles study

    KAUST Repository

    Bououdina, Mohamed

    2015-03-26

    We obtain a single cadmium oxide phase from powder synthesized by a thermal decomposition method of cadmium acetate dehydrate. The yielded powder is annealed in air, vacuum, and H2 gas in order to create point defects. Magnetization-field curves reveal the appearance of diamagnetic behavior with a ferromagnetic component for all the powders. Powder annealing under vacuum and H2 atmosphere leads to a saturation magnetization 1.15 memu g-1 and 1.2 memu g-1 respectively with an increase by 45% and 16% compared to the one annealed in air. We show that annealing in vacuum produces mainly oxygen vacancies while annealing in H2 gas creates mainly Cd vacancy leading to room temperature ferromagnetic (RTFM) component together with known diamagnetic properties. Ab initio calculations performed on the CdO nanoparticles show that the magnetism is governed by polarized hybrid states of the Cd d and O p orbitals together with the vacancy. © The Royal Society of Chemistry 2015.

  11. On the sensitivity to partial pressure of oxygen of the mobility in cadmium oxide

    Science.gov (United States)

    Grado-Caffaro, M. A.; Grado-Caffaro, M.

    2015-11-01

    The partial pressure of oxygen during the deposition process of cadmium oxide is a crucial quantity whose influence on the electrical and optical properties of this material is really very significant (consider, for example, the experimental technique known as activated reactive evaporation). In fact, this paper is a theoretical formulation to evaluate the sensitivity changes of the aforementioned pressure of the electron drift-mobility and velocity in CdO. Indeed, as we will see later, given that the electron relaxation time depends upon the oxygen partial pressure, then the electron drift-mobility, mean free path and velocity also depend on this pressure. Relevant calculations involving the above physical quantities are carried out.

  12. Study of removal of Direct Yellow 12 by cadmium oxide nanowires loaded on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, Mehrorang, E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Sadeghian, Batuol [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Kokhdan, Syamak Nasiri, E-mail: syamak.nasiri@yahoo.com [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Pebdani, Arezou Amiri [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Sahraei, Reza; Daneshfar, Ali; Mihandoost, Asma [Department of Chemistry, University of Ilam, P.O. Box: 65315-516, Ilam (Iran, Islamic Republic of)

    2013-05-01

    In this research, cadmium oxide nanowires loaded on activated carbon (CdO-NW-AC) has been synthesized by a simple procedure and characterized by different techniques such as XRD, SEM and UV–vis spectrometry. This new adsorbent has been efficiently utilized for the removal of the Direct Yellow 12 (DY-12) from wastewater. To obtain maximum DY-12 removal efficiency, the influences of variables such as pH, DY-12 concentration, amount of CdO-NW-AC, contact time, and temperature have been examined and optimized in a batch method. Following the variable optimization, the experimental equilibrium data (at different concentration of DY-12) was fitted to conventional isotherm models such as Langmuir, Freundlich and Tempkin. The applicability of each method is based on the R{sup 2} and error analysis for each model. It was found that the experimental equilibrium data well fitted to the Langmuir isotherm model. The dependency of removal process to time and the experimental data follow second order kinetic model with involvement of intraparticle diffusion model. The negative value of Gibbs's free energy and positive value of adsorption enthalpy show the spontaneous and endothermic nature of adsorption process. - Graphical abstract: Typical FE-SEM image of the CdO nanowires. Highlights: ► Cadmium oxide nanowires loaded on activated carbon was utilized as an adsorbent. ► It was used for the removal of Direct Yellow 12 from aqueous solutions. ► The adsorption of Direct Yellow 12 on this adsorbent is endothermic in nature. ► The adsorption equilibrium data was well described by the Langmuir isotherm model.

  13. Modelling toluene oxidation : Incorporation of mass transfer phenomena

    NARCIS (Netherlands)

    Hoorn, J.A.A.; van Soolingen, J.; Versteeg, G. F.

    2005-01-01

    The kinetics of the oxidation of toluene have been studied in close interaction with the gas-liquid mass transfer occurring in the reactor. Kinetic parameters for a simple model have been estimated on basis of experimental observations performed under industrial conditions. The conclusions for the m

  14. Residue incorporation depth is a controlling factor of earthworm-induced nitrous oxide emissions

    NARCIS (Netherlands)

    Paul, B.K.; Lubbers, I.M.; Groenigen, van J.W.

    2012-01-01

    Earthworms can increase nitrous oxide (N2O) emissions, particularly in no-tillage systems where earthworms are abundant. Here, we study the effect of residue incorporation depth on earthworm-induced N2O emissions. We hypothesized that cumulative N2O emissions decrease with residue incorporation dept

  15. Uranium and cadmium provoke different oxidative stress responses in Lemna minor L.

    Science.gov (United States)

    Horemans, N; Van Hees, M; Van Hoeck, A; Saenen, E; De Meutter, T; Nauts, R; Blust, R; Vandenhove, H

    2015-01-01

    Common duckweed (Lemna minor L.) is ideally suited to test the impact of metals on freshwater vascular plants. Literature on cadmium (Cd) and uranium (U) oxidative responses in L. minor are sparse or, for U, non-existent. It was hypothesised that both metals impose concentration-dependent oxidative stress and growth retardation on L. minor. Using a standardised 7-day growth inhibition test, the adverse impact of these metals on L. minor growth was confirmed, with EC50 values for Cd and U of 24.1 ± 2.8 and 29.5 ± 1.9 μm, respectively, and EC10 values of 1.5 ± 0.2 and 6.5 ± 0.9 μm, respectively. The metal-induced oxidative stress response was compared through assessing the activity of different antioxidative enzymes [catalase, glutathione reductase, superoxide dismutase (SOD), ascorbate peroxidase (APOD), guaiacol peroxidase (GPOD) and syringaldizyne peroxidase (SPOD)]. Significant changes in almost all antioxidative enzymes indicated their importance in counteracting the U- and Cd-imposed oxidative burden. However, some striking differences were also observed. For activity of APODs and SODs, a biphasic but opposite response at low Cd compared to U concentrations was found. In addition, Cd (0.5-20 μm) strongly enhanced plant GPOD activity, whereas U inhibited it. Finally, in contrast to Cd, U up to 10 μm increased the level of chlorophyll a and b and carotenoids. In conclusion, although U and Cd induce similar growth arrest in L. minor, the U-induced oxidative stress responses, studied here for the first time, differ greatly from those of Cd. PMID:25073449

  16. Magnesium oxide-impregnated tuff soil-derived ceramic: a novel cadmium(II) adsorbing media

    Science.gov (United States)

    Salim, Md; Bhakta, Jatindra N.; Maneesh, Namburath; Munekage, Yukihiro; Motomura, Kevin

    2015-07-01

    The contamination of cadmium (Cd) in the aquatic environment is one of the serious environmental and human health's risks. The present study attempted to develop the potential magnesium oxide (MgO)-impregnated tuff soil-derived ceramic (MITDC)-based novel adsorbent media for adsorbing higher rate of cadmium [Cd(II)] from water phase. A potential MITDC adsorbent media was developed using volcanic raw tuff soil and its Cd(II) adsorption capacity from water phase was evaluated comparing with the raw tuff soil. A series of studies were carried out in an agitated batch method at 20 ± 2 °C to characterize the adsorption capacity of MITDC under different conditions of factors, such as contact time (0-360 min), initial pH (3-11) of solution, dose of MITDC (2, 5, 7.5 and 10 g/L), and initial concentration of Cd(II) (5, 10, 20, 30, and 40 mg/L), influencing the adsorption mechanism. MITDC exhibited the equilibrium state of maximum Cd(II) adsorption at the contact time 120 min and pH 4.7 (removed 98.2 % Cd) when initial Cd(II) concentration was 10 mg/L in the present study. The dose of 7.5 g MITDC/L showed maximum removal of Cd(II) from water. Experimental data were described by the Freundlich and the Langmuir isotherms and equilibrium data fitted well with the Langmuir model (R 2 = 0.996). The Cd(II) adsorption capacity of MITDC was 31.25 mg/g. The high Cd(II) adsorption capacity indicated that novel MITDC could be used as a potential ceramic adsorbent media to remove high rate of Cd(II) from aqueous phase.

  17. Oxidative Stress and Cell Apoptosis in Caprine Liver Induced by Molybdenum and Cadmium in Combination.

    Science.gov (United States)

    Yang, Fan; Zhang, Caiying; Zhuang, Yu; Gu, Xiaolong; Xiao, Qingyang; Guo, Xiaoquan; Hu, Guoliang; Cao, Huabin

    2016-09-01

    To investigate the effects of co-exposure to molybdenum (Mo) and cadmium (Cd) on oxidative stress and cell apoptosis in caprine livers, 36 Boer goats were randomly divided into four groups with nine goats in each group. Three groups were randomly assigned with one of three oral treatments of CdCl2 (0.5 mg Cd kg(-1)·BW) and [(NH4)6Mo7O24·4H2O] (15 mg Mo kg(-1)·BW, 30 mg Mo kg(-1)·BW, 45 mg Mo kg(-1)·BW), while the control group received deionized water. Liver tissues on days 0, 25, and 50 were subjected to determine antioxidant activity indexes and the messenger RNA (mRNA) expression levels of ceruloplasmin (CP), cysteinyl aspartate-specific proteinase-3 (caspase-3), second mitochondria-derived activator of caspases (Smac), and cytochrome-C (Cyt-C) genes. The results showed that significant reductions were observed in total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) activities (P < 0.05), while activities or contents of malondialdehyde (MDA), nitric oxide (NO), and nitric oxide synthase (NOS) were increased (P < 0.05). The mRNA expression levels of CP, caspase-3, Smac, and Cyt-C genes were upregulated (P < 0.05). In addition, histopathological lesions showed different degrees of vacuolar degeneration and edematous and mitochondrial swelling. The results suggest that co-exposure to Mo and Cd could induce oxidative stress and cell apoptosis possibly associated with mitochondrial intrinsic pathway in goat liver and show possible synergistic effects between the two elements. PMID:26883837

  18. Polyhydroxyfullerene binds cadmium ions and alleviates metal-induced oxidative stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Pradhan, Arunava; Pinheiro, José Paulo; Seena, Sahadevan; Pascoal, Cláudia; Cássio, Fernanda

    2014-09-01

    The water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeast Saccharomyces cerevisiae by exposing cells to Cd (≤5 mg liter(-1)) in the absence or presence of PHF (≤500 mg liter(-1)) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.

  19. Enhancement of tolerance of Ganoderma lucidum to cadmium by nitric oxide.

    Science.gov (United States)

    Guo, Shanshan; Yao, Yuan; Zuo, Lei; Shi, Wenjin; Gao, Ni; Xu, Heng

    2016-01-01

    Nitric oxide (NO) is considered as a signaling molecule involved in regulation of diverse physiological processes and stress responses in animals and plants. However, whether NO regulates fungal, particularly edible fungi, response to heavy metal stresses, is unknown. This study investigated the effect of nitric oxide on biological responses of mycelia of Ganoderma lucidum to cadmium (Cd) toxicity. Exposure of Ganoderma lucidum to Cd (400 µM) triggered production of H2O2 and O2(-) in the mycelia and further induced lipid peroxidation as well as sharply decrease of fresh biomass. However, such an effect can be reversed by exogenous supply of NO. Mycelia treated with 100 µM SNP accumulated less H2O2, O2(-), thiobarbituric acid reactive substances (TBARS), and fresh biomass of this treatment was improved. Treatment with SNP significantly increased activities of antioxidant enzyme (peroxidase and catalase) to resist Cd stress. Meanwhile, NO-mediated alleviation of Cd toxicity was closely related to the accumulated proline as well as reduced Cd accumulation. These results suggested that NO plays a crucial role in preventing the mycelia of Ganoderma lucidum from Cd toxicity.

  20. Influences of indium doping and annealing on microstructure and optical properties of cadmium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuankun [University of Shanghai for Science and Technology, School of Materials Science and Engineering, Shanghai (China); Lei, Pei; Zhu, Jiaqi; Han, Jiecai [Harbin Institute of Technology, Center for Composite Materials, Harbin (China)

    2016-04-15

    The influences of indium doping and subsequent annealing in nitrogen and air atmospheres on the microstructure and optical properties of cadmium oxide films were studied in detail with the aid of various characterizations. X-ray photoelectronic spectroscopy analysis shows that indium atom forms chemically oxidized bonds in Cd-O matrix. X-ray diffraction results demonstrate that CdO structure remains FCC structure with indium doping, whereas the preferential orientation transforms from (222) into (200) orientation. Indium doping prevents the large crystalline growth, and this role still works under both nitrogen and air annealing processes. Similarly, CdO films show rough surface under annealing conditions, but the force has been greatly weakened at high doping level. It is clear that refractive index and extinction coefficient are closely correlated with crystalline size for undoped films, whereas it turns to the doping level for doped films, which can be performed by the mechanism of indium atom substitution. This work provides a very useful guild for design and application of optical-electronic devices. (orig.)

  1. Enhancement of tolerance of Ganoderma lucidum to cadmium by nitric oxide.

    Science.gov (United States)

    Guo, Shanshan; Yao, Yuan; Zuo, Lei; Shi, Wenjin; Gao, Ni; Xu, Heng

    2016-01-01

    Nitric oxide (NO) is considered as a signaling molecule involved in regulation of diverse physiological processes and stress responses in animals and plants. However, whether NO regulates fungal, particularly edible fungi, response to heavy metal stresses, is unknown. This study investigated the effect of nitric oxide on biological responses of mycelia of Ganoderma lucidum to cadmium (Cd) toxicity. Exposure of Ganoderma lucidum to Cd (400 µM) triggered production of H2O2 and O2(-) in the mycelia and further induced lipid peroxidation as well as sharply decrease of fresh biomass. However, such an effect can be reversed by exogenous supply of NO. Mycelia treated with 100 µM SNP accumulated less H2O2, O2(-), thiobarbituric acid reactive substances (TBARS), and fresh biomass of this treatment was improved. Treatment with SNP significantly increased activities of antioxidant enzyme (peroxidase and catalase) to resist Cd stress. Meanwhile, NO-mediated alleviation of Cd toxicity was closely related to the accumulated proline as well as reduced Cd accumulation. These results suggested that NO plays a crucial role in preventing the mycelia of Ganoderma lucidum from Cd toxicity. PMID:26411634

  2. OXIDATIVE STRESS IN SHEEP INDUCED BY CADMIUM CHLORIDE TOXICITY, WITH THERAPEUTIC EFFECTS OF ALPHA LIPOIC ACID

    OpenAIRE

    Hussien Ali NAJI; Mohammad Mushgil ZENAD

    2015-01-01

    Cadmium (Cd) is a heavy toxic metal, with harmful effects on animals and public health. Recently the risk of cadmium toxicity is substantially regarded; the environmental pollution is increased due to multi- uses of this element in various industries. This study was performed to clarify the effects of acute cadmium toxicity in sheep with trail of using alpha lipoic acid as an antioxidant therapeutic substance. Fifteen male lambs aged from 5-to-7 months were divided equally in to three groups,...

  3. Localisation of the sites of action of cadmium on oxidative phosphorylation in potato tuber mitochondria using top-down elasticity analysis.

    Science.gov (United States)

    Kesseler, A; Brand, M D

    1994-11-01

    The aim of this study was to identify the significant sites of action of cadmium on oxidative phosphorylation in potato tuber mitocondria. We simplified the system to three convenient subsystems linked via the production or consumption of a common intermediate, namely protonmotive force. The three subsystems were substrate oxidation, which produces protonmotive force, and the proton leak reactions and the phosphorylation reactions, which consume protonmotive force. By measuring the effect of cadmium on the kinetic response of each subsystem to protonmotive force (top-down elasticity analysis), we found that cadmium stimulated proton leak reactions and strongly inhibited substrate oxidation, but had no measurable effect on the phosphorylation reactions. Cadmium therefore decreases the amount of ATP produced/oxygen consumed (the effective P/O ratio) not by inhibiting the phosphorylation reactions directly, but by inhibiting the production of protonmotive force and by diverting proton flux from phosphorylation reactions to the proton leak reactions. PMID:7957227

  4. Hyperbranched polyether hybrid nanospheres with CdSe quantum dots incorporated for selective detection of nitric oxide

    DEFF Research Database (Denmark)

    Liu, Shuiping; Jin, Lanming; Chronakis, Ioannis S.;

    2014-01-01

    In this work, hybrid nanosphere vehicles consisting of cadmium selenide quantum dots (CdSe QDs) were synthesized for nitric oxide (NO) donating and real-time detecting. The nanospheres with QDs being encapsulation have spherical outline with dimension of ~127 nm. The fluorescence properties...

  5. Cardioprotective and Antioxidant Influence of Aqueous Extracts from Sesamum indicum Seeds on Oxidative Stress Induced by Cadmium in Wistar Rats

    Science.gov (United States)

    Oyinloye, Babatunji Emmanuel; Ajiboye, Basiru Olaitan; Ojo, Oluwafemi Adeleke; Nwozo, Sarah Onyenibe; Kappo, Abidemi Paul

    2016-01-01

    Background: Oxidative stress has been implicated in the pathogenesis of several acute and chronic diseases of the heart as a result of indiscriminate exposure to cardiotoxic heavy metals. The study reported here was designed to evaluate the possible ameliorative effect of aqueous extracts from Sesamum indicum (SI) seeds on oxidative stress induced by cadmium (Cd) in Wistar rats. Materials and Methods: Daily administration of Cd (200 mg/L Cd as CdCl2) in the animals’ main drinking water for 21 days led to oxidative stress. Thereafter, the ameliorative effects were assessed by measuring biochemical parameters such as extent of lipid peroxidation (LPO), lipid profile, and enzymatic and nonenzymatic antioxidants, as well as serum aminotransferase activities. Results: Treatment with SI extract elicited notable reduction in serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels as well as concomitant increase in high-density lipoprotein cholesterol. SI extract also reversed the elevations witnessed in serum aminotransferase activities, LPO level, and ameliorated enzymatic and nonenzymatic antioxidant status in the heart of Cd-exposed rats. Conclusion: Thus, SI appears to be an attractive candidate with potential for the novel treatment of cardiotoxicity and management of oxidative stress arising from Cd exposure. SUMMARY Cadmium (200 mg/L) exposure in drinking water caused pronounced oxidative stress and cardiac tissue damage in animal modelAqueous extract of Sesamum indicum (SI) seeds at a dose of 200 or 400 mg/kg body weight exhibited a significant reversal effect in all biochemical parameters measured such as extent of lipid peroxidation, lipid profile, and enzymatic and nonenzymatic antioxidants, as well as serum aminotransferase activitiesAqueous extract of SI seeds possess antioxidant and cardioprotective potential in a dose-dependent manner, thus conferring protection against oxidative stress induced by cadmium. Abbreviation used

  6. CADMIUM SOLUBILITY IN PADDY SOILS: EFFECTS OF SOIL OXIDATION, METAL SULFIDES AND COMPETITIVE IONS.

    Science.gov (United States)

    Cadmium (Cd) is a non-essential element for human nutrition and is an agricultural soil contaminant. Cadmium solubility in paddy soils affects Cd accumulation in the grain of rice. This is a human health risk, exacerbated by the fact that rice grains are deficient in iron (Fe) an...

  7. One-pot synthesis of reduced graphene oxide-cadmium sulfide nanocomposite and its photocatalytic hydrogen production.

    Science.gov (United States)

    Zeng, Peng; Zhang, Qinggang; Peng, Tianyou; Zhang, Xiaohu

    2011-12-28

    Reduced graphene oxide (RGO)-cadmium sulfide (CdS) nanocomposites were successfully prepared by a one-pot solvothermal process without pretreatment of graphene oxide (GO) and a precipitation process, in which GO needs to be pre-reduced by hydrazine. The as-obtained RGO-CdS nanocomposites were used as photocatalysts for hydrogen production under visible light irradiation, and it was found that the product derived from the one-pot solvothermal process showed much better photoactivity than that from the precipitation method. PMID:22068902

  8. Inhaled Cadmium Oxide Nanoparticles: Their in Vivo Fate and Effect on Target Organs

    Science.gov (United States)

    Dumkova, Jana; Vrlikova, Lucie; Vecera, Zbynek; Putnova, Barbora; Docekal, Bohumil; Mikuska, Pavel; Fictum, Petr; Hampl, Ales; Buchtova, Marcela

    2016-01-01

    The increasing amount of heavy metals used in manufacturing equivalently increases hazards of environmental pollution by industrial products such as cadmium oxide (CdO) nanoparticles. Here, we aimed to unravel the CdO nanoparticle destiny upon their entry into lungs by inhalations, with the main focus on the ultrastructural changes that the nanoparticles may cause to tissues of the primary and secondary target organs. We indeed found the CdO nanoparticles to be transported from the lungs into secondary target organs by blood. In lungs, inhaled CdO nanoparticles caused significant alterations in parenchyma tissue including hyperemia, enlarged pulmonary septa, congested capillaries, alveolar emphysema and small areas of atelectasis. Nanoparticles were observed in the cytoplasm of cells lining bronchioles, in the alveolar spaces as well as inside the membranous pneumocytes and in phagosomes of lung macrophages. Nanoparticles even penetrated through the membrane into some organelles including mitochondria and they also accumulated in the cytoplasmic vesicles. In livers, inhalation caused periportal inflammation and local hepatic necrosis. Only minor changes such as diffusely thickened filtration membrane with intramembranous electron dense deposits were observed in kidney. Taken together, inhaled CdO nanoparticles not only accumulated in lungs but they were also transported to other organs causing serious damage at tissue as well as cellular level. PMID:27271611

  9. Inhaled Cadmium Oxide Nanoparticles: Their in Vivo Fate and Effect on Target Organs

    Directory of Open Access Journals (Sweden)

    Jana Dumkova

    2016-06-01

    Full Text Available The increasing amount of heavy metals used in manufacturing equivalently increases hazards of environmental pollution by industrial products such as cadmium oxide (CdO nanoparticles. Here, we aimed to unravel the CdO nanoparticle destiny upon their entry into lungs by inhalations, with the main focus on the ultrastructural changes that the nanoparticles may cause to tissues of the primary and secondary target organs. We indeed found the CdO nanoparticles to be transported from the lungs into secondary target organs by blood. In lungs, inhaled CdO nanoparticles caused significant alterations in parenchyma tissue including hyperemia, enlarged pulmonary septa, congested capillaries, alveolar emphysema and small areas of atelectasis. Nanoparticles were observed in the cytoplasm of cells lining bronchioles, in the alveolar spaces as well as inside the membranous pneumocytes and in phagosomes of lung macrophages. Nanoparticles even penetrated through the membrane into some organelles including mitochondria and they also accumulated in the cytoplasmic vesicles. In livers, inhalation caused periportal inflammation and local hepatic necrosis. Only minor changes such as diffusely thickened filtration membrane with intramembranous electron dense deposits were observed in kidney. Taken together, inhaled CdO nanoparticles not only accumulated in lungs but they were also transported to other organs causing serious damage at tissue as well as cellular level.

  10. Inhaled Cadmium Oxide Nanoparticles: Their in Vivo Fate and Effect on Target Organs.

    Science.gov (United States)

    Dumkova, Jana; Vrlikova, Lucie; Vecera, Zbynek; Putnova, Barbora; Docekal, Bohumil; Mikuska, Pavel; Fictum, Petr; Hampl, Ales; Buchtova, Marcela

    2016-01-01

    The increasing amount of heavy metals used in manufacturing equivalently increases hazards of environmental pollution by industrial products such as cadmium oxide (CdO) nanoparticles. Here, we aimed to unravel the CdO nanoparticle destiny upon their entry into lungs by inhalations, with the main focus on the ultrastructural changes that the nanoparticles may cause to tissues of the primary and secondary target organs. We indeed found the CdO nanoparticles to be transported from the lungs into secondary target organs by blood. In lungs, inhaled CdO nanoparticles caused significant alterations in parenchyma tissue including hyperemia, enlarged pulmonary septa, congested capillaries, alveolar emphysema and small areas of atelectasis. Nanoparticles were observed in the cytoplasm of cells lining bronchioles, in the alveolar spaces as well as inside the membranous pneumocytes and in phagosomes of lung macrophages. Nanoparticles even penetrated through the membrane into some organelles including mitochondria and they also accumulated in the cytoplasmic vesicles. In livers, inhalation caused periportal inflammation and local hepatic necrosis. Only minor changes such as diffusely thickened filtration membrane with intramembranous electron dense deposits were observed in kidney. Taken together, inhaled CdO nanoparticles not only accumulated in lungs but they were also transported to other organs causing serious damage at tissue as well as cellular level. PMID:27271611

  11. Influence of pH of spray solution on optoelectronic properties of cadmium oxide thin films

    International Nuclear Information System (INIS)

    Highly conducting transparent cadmium oxide thin films were prepared by the conventional spray pyrolysis technique. The pH of the spray solution is varied by adding ammonia/hydrochloric acid. The effect of pH on the morphology, crystallinity and optoelectronic properties of these films is studied. The structural analysis showed all the films in the cubic phase. For the films with pH < 7 (acidic condition), the preferred orientation is along the (111) direction and for those with pH >7 (alkaline condition), the preferred orientation is along the (200) direction. A lowest resistivity of 9.9 × 10−4 Ω·cm (with carrier concentration = 5.1 × 1020 cm−3, mobility = 12.4 cm2/(V·s)) is observed for pH ≈ 12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70%. Thus, the electrical conductivity of CdO films could be easily tuned by simply varying the pH of the spray solution without compromising the optical transparency. (paper)

  12. Analysis of metal profile in soybean after cadmium-induced oxidative damage

    Institute of Scientific and Technical Information of China (English)

    Emiliano Felici; Cesar Almeida; Martin Fernndez Baldo; Luis D Martnez; Fanny Zirulnik; Mara R Gomez

    2014-01-01

    Objective: To analyze the effect of cadmium (Cd) on soybean seedlings growth and the relationship with the distribution and concentration of macro-microelements. Methods: The ions concentrations were determined by ICP-MS. The extraction efficiency and digestion time were optimized. Also, oxidative stress parameters were determined and related with metal content. Results:The accumulated amount of dry matter in roots and leaves was lower in the Cd-treated group. Regression analysis showed that the exposure to Cd affected the accumulated amount of dry matter as well as the content of mineral elements in the analysis samples. In Cd treated plants, electrical conductivity increased respect to the controls, indicating that ionic permeability became altered. A strong inhibition of the chlorophylls (chl) biosynthesis in the Cd-treated group was also demonstrated by a decrease of chla and chlb concentration. This result was related with the observed significant decrease in the Mg uptake at the roots and leaves level. Conclusions: The stress caused by Cd exposure, evidenced by significantly high hydrogen peroxide levels in roots and leaves after 24 h and the content of specific macro-microelements is a factor that affects the accumulation of dry matter, electrical conductivity and chlorophylls concentration.

  13. Immunohistochemical Study of Nrf2-Antioxidant Response Element as Indicator of Oxidative Stress Induced by Cadmium in Developing Rats

    Directory of Open Access Journals (Sweden)

    Sergio Montes

    2015-01-01

    Full Text Available In developing animals, Cadmium (Cd induces toxicity to many organs including brain. Reactive oxygen species (ROS are often implicated in Cd-inducedtoxicity and it has been clearly demonstrated that oxidative stress interferes with the expression of genes as well as transcriptional factors such as Nrf2-dependent Antioxidant Response Element (Nrf2-ARE. Cd-generated oxidative stress and elevated Nrf2 activity have been reported in vitro and in situ cells. In this study we evaluated the morphological changes and the expression pattern of Nrf2 and correlated them with the Cd concentrations in different ages of developing rats in heart, lung, kidney, liver, and brain. The Cd content in different organs of rats treated with the metal was increased in all ages assayed. Comparatively, lower Cd brain levels were found in rats intoxicated at the age of 12 days, then pups treated at 5, 10, or 15 days old, at the same metal dose. No evident changes, as a consequence of cadmium exposure, were evident in the morphological analysis in any of the ages assayed. However, Nrf2-ARE immunoreactivity was observed in 15-day-old rats exposed to Cd. Our results support that fully developed blood-brain barrier is an important protector against Cd entrance to brain and that Nrf2 increased expression is a part of protective mechanism against cadmium-induced toxicity.

  14. Endogenous nitric oxide mediates alleviation of cadmium toxicity induced by calcium in rice seedlings

    Institute of Scientific and Technical Information of China (English)

    Long Zhang; Zhen Chen; Cheng Zhu

    2012-01-01

    The effect of calcium chloride (CaCl2) on rice seedling growth under cadmium chloride (CdCl2) stress,as well as the possible role of endogenous nitric oxide (NO) in this process,was studied.The growth of rice seedlings was seriously inhibited by CdCl2,and the inhibition was significantly mitigated by CaCl2.However,hemoglobin (Hb) and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline1-oxyl-3-oxide (cPTIO) weakened the promotion effect of CaCl2.The resuhs of NO fluorescence localization suggest that growth accelerated by CaCl2 might be associated with elevated NO levels.The content of Cd,protein thiols (PBT),and nonprotein thiols (NPT) in cell walls,cell organelles,and soluble fractions,respectively,of rice seedlings decreased considerably in the presence of CaCl2,whereas the content of pectin,hemicellulose 1 (HC1),and hemicellulose 2 (HC2) increased significantly.Elimination of endogenous NO in Cd+Ca treatment could promote the transportation of Cd2+ to cell organelles and soluble fractions and increase the content of NPT and PBT in leaves.In addition,transportation of Cd2+ to cell organelles and soluble fractions was retarded in roots,the content of NPT increased,and the content of PBT decreased.With elimination of endogenous NO in Cd+Ca treatment,the content of pectin,HC 1,and HC2 decreased significantly.Thus,Ca may alleviate Cd toxicity via endogenous NO with variation in the levels of NPT,PBT,and matrix polysaccharides.

  15. Effect of Nitric Oxide on Alleviating Cadmium Toxicity in Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiu-feng; CHEN Lin; Muhammad IA Rehmani; WANG Qiang-sheng; WANG Shao-hua; HOU Peng-fu; LI Gang-hua; DING Yan-feng

    2013-01-01

    Nitric oxide (NO) is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to investigate the effects of the exogenous application of sodium nitroprusside (SNP), an NO donor, on cadmium (Cd)-induced oxidative stress and Cd uptake in rice plants. Rice plants were exposed to Cd stress (0.2 mmol L-1 CdCl2) and different concentrations of SNP (0.05, 0.1, 0.2, and 0.4 mmol L-1). A SNP concentration of 0.1 mmol L-1 (SNP10) significantly reduced the Cd-induced decrease in shoot and root dry weights and leaf chlorophyll concentrations. The addition of NO also reduced the malondialdehyde (MDA), hydrogen peroxide (H2O2) and ascorbic acid (ASA) concentrations. However, the reduction in glutathione (GSH) concentration was inhibited by NO treatment. Moreover, NO prevented the Cd-induced increase in antioxidative enzyme activity. The amount of Cd accumulation in rice plants was also influenced by the addition of NO. The NO supplied by the SNP enhanced the Cd tolerance of the rice by increasing the Cd uptake by the roots and decreasing the Cd accumulation by the shoots. However, the application of potassium ferrocyanide (Cd+Fe) or sodium nitrate and nitrite (Cd+N) (without NO release), did not exhibit the effects of the SNP. Furthermore, the effects of the SNP were reversed by the addition of hemoglobin (an NO scavenger). Our results suggested that exogenous NO was involved in the resistance of rice to Cd-toxicity.

  16. Effects of Exposure to Lead and Cadmium on the Oxidative Damage of Livers in Laying Hens

    Institute of Scientific and Technical Information of China (English)

    Chen; Dawei; Pu; Junhua; Tang; Xiujun; Lu; Junxian; Liu; Yinyin; Jia; Xiaoxu; Ge; Qinglian; Gao; Yushi

    2014-01-01

    [Objective] To detect the effects of exposure to lead and cadmium on the oxidative damage of livers in laying hens. [Methods] One hundred and twenty 40-week-old Hyline brown hens were randomly divided into four groups. 100 mg / L Pb and / or 50 mg / L Cd was added into the drinking water for eight weeks. [Results] Compared with control group,AST and ALT activities in Pb group enhanced; but there were no significant differences. AST and ALT activities in Cd group and( Pb + Cd) group significantly or extremely significantly increased( P < 0. 05 or P < 0. 01). SOD activity,GSH- Px activity and GSH content in( Pb + Cd) group,Cd group and Pb group were significantly or extremely significantly lower than those in control group( P <0. 05 or P <0. 01). Among them,( Pb + Cd) group showed the greatest reduction( P <0. 01). MDA contents in the three groups were significantly higher than that of control group; and( Pb +Cd) group was significantly higher than Pb group and Cd group. Cu,Fe and Zn contents in three groups were higher than those in control group in different degrees( P <0. 05 or P <0. 01). Se contents in Cd group and( Pb + Cd) group were significantly lower than that in control group( P <0. 01). Residue contents in livers in Pb group and Cd group were significantly greater than that in control group; while residue content in( Pb + Cd) group was significantly higher than those in Pb group and Cd group. Ultrastructure showed that there were symptoms of mitochondrial swelling and fractured cristae in liver cells of laying hens after the exposure to Cd and Pb. In( Pb + Cd) group,these symptoms were even greater. [Conclusion] Oxidative damage and disturbance of trace element metabolism were one of the mechanisms for hepatotocity in laying hens induced by Pb and Cd,and synergistic effect lied in the coadministration.

  17. Temperature dependence of long-term cadmium toxicity in the zebrafish is not explained by liver oxidative stress: Evidence from transcript expression to physiology

    Energy Technology Data Exchange (ETDEWEB)

    Vergauwen, Lucia, E-mail: lucia.vergauwen@ua.ac.be [Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Hagenaars, An, E-mail: an.hagenaars@ua.ac.be [Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Blust, Ronny, E-mail: ronny.blust@ua.ac.be [Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Knapen, Dries, E-mail: dries.knapen@ua.ac.be [Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Gamete Research Center (GRC), Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2013-01-15

    Standard ecotoxicity tests are performed at species' specific standard temperatures, but temperature is known to affect chemical toxicity. A temperature increase has been shown to increase cadmium toxicity in several aquatic species but information in fish is scarce. Based on literature we hypothesize that with increasing temperature, cadmium accumulation and oxidative stress increase, resulting in increased toxicity. In this study zebrafish acclimated to 12, 18, 26 (standard temperature) or 34 Degree-Sign C for one month, were exposed to 5 {mu}M cadmium for 4 or 28 days at the respective acclimation temperature. Cadmium toxicity (mortality) increased with increasing temperature. PCA showed that the high mortality at 34 Degree-Sign C was closely correlated to an increasing tissue cadmium accumulation with increasing temperature, but not to liver oxidative damage under the form of protein carbonyl content or lipid peroxidation (measured as malondialdehyde levels) or liver antioxidative potential. Instead, acclimation to 12 Degree-Sign C induced the highest oxidative damage to liver proteins and lipids, and transcript levels of glucose-6P-dehydrogenase, 6P-gluconate-dehydrogenase and glutathione peroxidase were particularly good markers of cold-induced oxidative stress. At this low temperature there was no interaction with cadmium exposure and there was no sign of cadmium sensitivity. Contrastingly, the combined effect of high temperature and cadmium exposure on mortality proved synergistic. Therefore we conclude that interactions between temperature and cadmium toxicity increased with increasing temperature and that this probably played part in increasing cadmium sensitivity. Increased cadmium compartmentalization and protein carbonyl content in liver of zebrafish acclimated to the standard temperature of 26 Degree-Sign C probably played part in increased sensitivity towards the same cadmium body burden compared to lower temperatures. On the one hand we

  18. Nitric oxide-releasing polymer incorporated ointment for cutaneous wound healing.

    Science.gov (United States)

    Kang, Youngnam; Kim, Jihoon; Lee, Yeong Mi; Im, Sooseok; Park, Hansoo; Kim, Won Jong

    2015-12-28

    This work demonstrates the development of nitric oxide-releasing ointment and its potential on efficient wound healing. Nitric oxide-releasing polymer was successfully synthesized, which is composed of biocompatible Pluronic F127, branched polyethylenimine and 1-substituted diazen-1-ium-1,2-diolates. The synthesized nitric oxide-releasing polymer was incorporated into the PEG-based ointment which not only facilitated nitric oxide release in a slow manner, but also served as a moisturizer to enhance the wound healing. As compared to control groups, the nitric oxide-releasing ointment showed the accelerated wound closure with enhanced re-epithelialization, collagen deposition, and blood vessel formation in vivo. Therefore, this nitric oxide-based ointment presents the promising potential for the efficient strategy to heal the cutaneous wound.

  19. 长期秸秆还田对德阳地区稻田土壤镉赋存形态的影响%Effects of long-term straw incorporation on cadmium speciation and bioavailability in paddy soils in Deyang Area

    Institute of Scientific and Technical Information of China (English)

    杨兰; 李冰; 王昌全; 肖瑞; 杨川; 李洲

    2015-01-01

    paddy soil was from Jinyang District, Deyang City, Sichuan Province. Field-investigated and field-sampled data were analyzed to determine the characteristics of cadmium fractions in straw-incorporated (returned rice straw into soil in autumn and returned wheat straw into soil in summer) paddy soils for 0, 1, 4 and 8 years. The results showed that the average content of total soil cadmium in the ploughing layer (0-20 cm soil layer) was 0.478 mg·kg-1. The average content of total soil cadmium in plough pan (20-40 cm soil layer) was 0.419 mg·kg-1. The average contents of cadmium in both soil layers exceeded environmental quality standard for agricultural soils (farmland soil cadmium Fe-Mn oxide bonded Cd > organically bonded Cd > carbonate bonded Cd > exchangeable Cd. The incorporation of crop straw for over 4 years in paddy soils significantly improved soil organic matter content. It also obviously increased soil organically bonded Cd ions.The content of organically bonded Cd in soil with crop straw incorporation for 4 years was increased by 45%. The incorporation of crop straw in paddy soils slightly increased soil exchangeable Cd in the ploughing layer (0-20 cm soil layer). With increasing years of the incorporation of crop straw into soil, soil pH initially increased significantly (crop straw incorporation for 1-4 years) before decreasing slowly (crop straw incorporation for 4-8 years). This mainly affected the speciation of soil carbonate bonded Cd. The bioavailability of soil cadmium speciation under different years of crop straw incorporation was evaluate too. For short term crop straw incorporation (1-4 years), the bioavailability of cadmium in ploughing soil layer (0-20 cm) significantly decreased with increasing number of years. However, the bioavailability of soil cadmium fractions in the plough pan (20-40 cm soil layer) did not significantly change with increasing number of years of crop straw incorporation. In conclusion therefore, short-term (1-4 years

  20. Waterborne cadmium and nickel impact oxidative stress responses and retinoid metabolism in yellow perch

    Energy Technology Data Exchange (ETDEWEB)

    Defo, Michel A. [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada); Bernatchez, Louis [Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec G1V 0A6 (Canada); Campbell, Peter G.C. [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada); Couture, Patrice, E-mail: patrice.couture@ete.inrs.ca [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada)

    2014-09-15

    Highlights: • Cd and Ni affected indicators of retinoid metabolism and oxidative stress in fish. • Liver rdh-2 transcription levels increase in fish exposed to waterborne Cd. • Liver REH and LdRAT activities increase with increasing kidney Cd concentration. • Changes at molecular levels do not always mean changes at the functional levels. • Multi-level biological approaches are needed when assessing fish metal toxicology. - Abstract: In this experiment, we studied the transcriptional and functional (enzymatic) responses of yellow perch (Perca flavescens) to metal stress, with a focus on oxidative stress and vitamin A metabolism. Juvenile yellow perch were exposed to two environmentally relevant concentrations of waterborne cadmium (Cd) and nickel (Ni) for a period of 6 weeks. Kidney Cd and Ni bioaccumulation significantly increased with increasing metal exposure. The major retinoid metabolites analyzed in liver and muscle decreased with metal exposure except at high Cd exposure where no variation was reported in liver. A decrease in free plasma dehydroretinol was also observed with metal exposure. In the liver of Cd-exposed fish, both epidermal retinol dehydrogenase 2 transcription level and corresponding enzyme activities retinyl ester hydrolase and lecithin dehydroretinyl acyl transferase increased. In contrast, muscle epidermal retinol dehydrogenase 2 transcription level decreased with Cd exposure. Among antioxidant defences, liver transcription levels of catalase, microsomal glutathione-S-transferase-3 and glucose-6-phosphate dehydrogenase were generally enhanced in Cd-exposed fish and this up-regulation was accompanied by an increase in the activities of corresponding enzymes, except for microsomal glutathione-S-transferase. No consistent pattern in antioxidant defence responses was observed between molecular and biochemical response when fish were exposed to Ni, suggesting a non-synchronous response of antioxidant defence in fish exposed to

  1. Arabidopsis HY1 Confers Cadmium Toleranceby Decreasing Nitric Oxide Production andImproving Iron Homeostasis

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Up-regulation of the gene that encodes intracellular heme oxygenase 1 (HO1) benefits plants under cad-mium (Cd2+) stress; however, the molecular mechanisms remain unclear. Here, we elucidate the role of Arabidopsis HY1(AtHO1) in Cd2+ tolerance by using genetic and molecular approaches. Analysis of two HY1 null mutants, three HY1 over-expression lines, HO double or triple mutants, as well as phyA and phyB mutants revealed the specific hypersensitivityof by1 to Cd2+ stress. Supplementation with two enzymatic by-products of HY1, carbon monoxide (CO) and iron (Fe,especially), rescued the Cd2+-induced inhibition of primary root (PR) elongation in hy1-100. The mutation of HY1, whichexhibited lower glutathione content than Col-0 in root tissues, was able to induce nitric oxide (NO) overproduction,Cd2+ accumulation, and severe Fe deficiency in root tissues. However, the contrasting responses appeared in 35S:HY1-4.Additionally, reduced levels of Ferric Reduction Oxidase 2 (FRO2) and Iron-Regulated Transporter 1 (IRT1) transcripts,and increased levels of Heavy Metal ATPase 2/4 (HMA2/4) transcripts bolster the notion that HY1 up-regulation amelio-rates Fe deficiency, and might increase Cd2+ exclusion. Taken together, these results showed that HY1 plays a commonlink in Cd2+ tolerance by decreasing NO production and improving Fe homeostasis in Arabidopsis root tissues.

  2. Lead and Cadmium Adsorption onto Iron Oxides and Manganese Oxides in the Natural Surface Coatings Collected on Natural Substances in the Songhua River of China

    Institute of Scientific and Technical Information of China (English)

    DONG De-ming; ZHAO Xing-min; HUA Xiu-yi; ZHANG Jing-jing; WU Shi-ming

    2007-01-01

    Natural surface coatings collected from natural substances(NSCsNS) were employed to study the roles of the main chemical components (iron oxides, manganese oxides, and other components) in controlling the adsorption of lead(Pb) and cadmium(Cd) in aquatic environments. The selective chemical extraction followed by the adsorption of Pb and Cd experiments and statistical analysis, were used to investigate the adsorption property of each component.Hydroxylamine hydrochloride was used to remove manganese oxides selectively, and sodium dithionite was used to extract iron oxides and manganese oxides. The result indicated that iron oxides and manganese oxides played an important role in the adsorption of Pb and Cd on NSCsNS, and the relative contribution was about two-thirds. The contribution of manganese oxides was the greatest, with a lesser role indicated for other components. The adsorption ability of manganese oxides for Pb and Cd was greater than that of iron oxides or other components for Pb and Cd. The Pb adsorption observed in each component was greater than Cd adsorption.

  3. Rapid Inactivation of Chloroplastic Ascorbate Peroxidase is Responsible for Oxidative Modification to Rubisco in Tomato (Lycopersicon esculentum) under Cadmium Stress

    Institute of Scientific and Technical Information of China (English)

    Kai-Lang Liu; Lin Shen; Jia-Qi Wang; Ji-Ping Sheng

    2008-01-01

    To investigate the sensitive site of antioxidant systems in chloroplast under cadmium stress and its consequence on reactive oxygen species production and action, the sub-organellar localization of chloroplast superoxide dismutases (SOD,EC 1.15.1.1) and ascorbic peroxidase (APX, EC 1.11.1.11) isoenzymes and changes of enzymes activities under cadmium stress were investigated in tomato seedlings. Two APX isoforms, one thylakoid-bound and one stromal, were detected. Cd at 50 μM induced a moderate increase of SOD activities but a rapid inactivation of both APX isoenzymes. APX inactivation was mainly related to the decrease of ascorbate concentration, as supported by in vitro treatment of exogenous ascorbate and APX kinetic properties under Cd stress. H2O2 accumulation in chloroplast, as a consequence of APX inactivation,was associated with a 60% loss of Rubisco (EC 4.1.1.39) activity, which could be partially accounted for by a 10% loss of Rubisco content. Protein oxidation assay found that the Rubisco large subunit was the most prominent carbonylated protein; the level of carbonylated Rubisco large subunit increased fivefold after Cd exposure. Thiol groups in the Rubisco large subunit were oxidized, as indicated by non-reducing electrophoresis. Treating crude extract with H2O2 resulted in a similar pattern of protein oxidation and thiols oxidation with that observed in Cd-treated plants. Our study indicates that APXs in the chloroplast is a highly sensitive site of antioxidant systems under Cd stress, and the inactivation of APX could be mainly responsible for oxidative modification to Rubisco and subsequent decrease in its activity.

  4. Subsurface Conditions Controlling Uranium Incorporation in Iron Oxides: A Redox Stable Sink

    Energy Technology Data Exchange (ETDEWEB)

    Fendorf, Scott [Stanford Univ., CA (United States)

    2016-04-05

    Toxic metals and radionuclides throughout the U.S. Department of Energy Complex pose a serious threat to ecosystems and to human health. Of particular concern is the redox-sensitive radionuclide uranium, which is classified as a priority pollutant in soils and groundwaters at most DOE sites owing to its large inventory, its health risks, and its mobility with respect to primary waste sources. The goal of this research was to contribute to the long-term mission of the Subsurface Biogeochemistry Program by determining reactions of uranium with iron (hydr)oxides that lead to long-term stabilization of this pervasive contaminant. The research objectives of this project were thus to (1) identify the (bio)geochemical conditions, including those of the solid-phase, promoting uranium incorporation in Fe (hydr)oxides, (2) determine the magnitude of uranium incorporation under a variety of relevant subsurface conditions in order to quantify the importance of this pathway when in competition with reduction or adsorption; (3) identify the mechanism(s) of U(VI/V) incorporation in Fe (hydr)oxides; and (4) determine the stability of these phases under different biogeochemical (inclusive of redox) conditions. Our research demonstrates that redox transformations are capable of achieving U incorporation into goethite at ambient temperatures, and that this transformation occurs within days at U and Fe(II) concentrations that are common in subsurface geochemical environments with natural ferrihydrites—inclusive of those with natural impurities. Increasing Fe(II) or U concentration, or initial pH, made U(VI) reduction to U(IV) a more competitive sequestration pathway in this system, presumably by increasing the relative rate of U reduction. Uranium concentrations commonly found in contaminated subsurface environments are often on the order of 1-10 μM, and groundwater Fe(II) concentrations can reach exceed 1 mM in reduced zones of the subsurface. The redox-driven U(V) incorporation

  5. Role of nitric oxide in cadmium-induced stress on growth, photosynthetic components and yield of Brassica napus L.

    Science.gov (United States)

    Jhanji, Shalini; Setia, R C; Kaur, Navjyot; Kaur, Parminder; Setia, Neelam

    2012-11-01

    Experiments were carried out to study the effect of cadmium (Cd) and exogenous nitric oxide (NO) on growth, photosynthetic attributes, yield components and structural features of Brassica napus L. (cv. GSL 1). Cadmium in the growth medium at different levels (1, 2 and 4 Mm) retarded plant growth viz. shoot (27%) and root (51%) length as compared to control. The accumulation of total dry matter and its partitioning to different plant parts was also reduced by 31% due to Cd toxicity. Photosynthetic parameters viz., leaf area plant(-1) (51%), total Chl (27%), Chl a / Chl b ratio (22%) and Hill reaction activity of chloroplasts (42%) were greatly reduced in Cd-treated plants. Cd treatments adversely affected various yield parameters viz., number of branches (23) and siliquae plant(-1) (246), seed number siliqua(-1) (10.3), 1000-seed weight (2.30g) and seed yield plant(-1) (7.09g). Different Cd treatments also suppressed the differentiation of various tissues like vessels in the root with a maximum inhibition caused by 4mM Cd. Exogenous application of nitric oxide (NO) improved the various morpho-physiological and photosynthetic parameters in control as well as Cd-treated plants. PMID:23741796

  6. Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?

    Energy Technology Data Exchange (ETDEWEB)

    Macías-Mayorga, Dayanara, E-mail: dayanara.macias@uleam.edu.ec [Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain); Departamento Central De Investigación (DCI), Universidad Laica Eloy Alfaro de Manabí, Vía San Mateo, Manta (Ecuador); Laiz, Irene [Departamento de Física Aplicada, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain); Moreno-Garrido, Ignacio; Blasco, Julián [Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain)

    2015-04-15

    Highlights: • The cadmium accumulation in C. angulata tended toward a stationary state. • Metallothionein-like protein (MTLP) is clearly induced by Cd accumulation. • The MTLP detoxification mechanism is affected at high Cd concentrations. • Cadmium toxicity causes GSH levels to decrease and inhibits antioxidant enzymes. - Abstract: The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system.

  7. Sputter fabricated Nb-oxide-Nb josephson junctions incorporating post-oxidation noble metal layers

    International Nuclear Information System (INIS)

    We present an extension, involving other metals, of the work of Hawkins and Clarke, who found that a thin layer of copper prevented the formation of the superconductive shorts which are an inevitable consequence of sputtering niobium counter-electrodes directly on top of niobium oxide. We find gold to be the most satisfactory, and that 0.3 nm is sufficient to guarantee short-free junctions of excellent electrical and mechanical stability, though high excess conductance means they are best suited to shunted-junction applications, as in SQUIDs. We present results for critical current dependence on oxide thickness and on gold thickness. Our data shows that thermal oxide growth is described by the Cabrera-Mott mechanism. We show that the protective effect of the gold layer can be understood in terms of the electro-chemistry of the Nb-oxide-Au structure, and that the reduced quasi-particle resistance of the junctions relative to goldfree junctions with evaporated counterelectrodes can be explained in terms of barrier shape modification, and not by proximity effect mechanisms. The performance of a DC SQUID based on these junctions is described

  8. Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

    International Nuclear Information System (INIS)

    An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 ± 4 cm and weight of 86 ± 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl2.H2O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl2.H2O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce

  9. Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Puneet, E-mail: puneetbiochem@gmail.com [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Prasad, Y. [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Patra, A.K. [West Bengal University of Animal and Fishery Sciences, Kolkata-700037 (India); Ranjan, R.; Swarup, D.; Patra, R.C. [Division of Medicine, Indian Veterinary Research Institute, Izatnagar-243122 (India); Pal, Satya [Env. Eng. Lab., Deptt. of Civil Engineering, I.I.T., Roorkee-247667 (India)

    2009-09-01

    An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 {+-} 4 cm and weight of 86 {+-} 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl{sub 2}.H{sub 2}O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl{sub 2}.H{sub 2}O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and

  10. Ameliorative effects of Rosmarinus officinalis leaf extract and Vitamin C on cadmium-induced oxidative stress in Nile tilapia Oreochromis niloticus.

    Science.gov (United States)

    Al-Anazi, Marim Saleh; Virk, Promy; Elobeid, Mai; Siddiqui, Muzammil Iqbal

    2015-11-01

    The present studywas undertaken to assess the bioaccumulation potential of cadmium in liver, kidney, gills and muscles of freshwater fish, Nile tilapia Oreochromis niloticus and the changes in oxidative stress indices in liver and kidney with or without simultaneous treatment with waterborne vitamin C and rosemary leaf extract. Adult tilapia were divided into seven groups. Six groups were exposed to sublethal concentrations of Cd, three groups to 5 ppm, while other three to 10 ppm. Two groups from each of the Cd exposed groups were treated with Vitamin C (5ppm) and rosemary leaf extract (2.5 ppm) for a period of 21 days. Cadmium concentration in liver, kidneys and gills was significantly higher in the cadmium exposed groups being invariably high in the groups exposed to 10 ppm CdCl2.H2O.Treatment with Vitamin C and rosemary leaf extract significantly reduced cadmium concentration in comparison to non-treated Cd exposed groups. Treatment with Vitamin C and rosemary leaf extract significantly reduced oxidative stress in Cd exposed fish as evidenced from lower concentration of lipid peroxides and reduced activity of catalase and higher activity of superoxide dismutase in liver and kidney as compared to control fish. Reduction in Cd induced oxidative stress and bioaccumulation was comparable between the two antioxidant treatments, Vitamin C and rosemary leaf extract. The key findings suggest that both the antioxidants used showed ameliorative potential to reduce tissue accumulation of Cd and associated oxidative stress in fresh water fish, Nile tilapia. PMID:26688980

  11. Associations of neonatal lead, cadmium, chromium and nickel co-exposure with DNA oxidative damage in an electronic waste recycling town

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Wenqing; Huang, Yue; Wang, Xiaoling; Zhang, Jingwen; Wu, Kusheng, E-mail: kswu@stu.edu.cn

    2014-02-01

    Objective: This study aimed to evaluate the effects of toxic heavy metal co-exposure on DNA oxidative damage in neonates from a primitive e-waste recycling region, Guiyu town, China. Methods: Our participants included 201 pregnant women: 126 from Guiyu town and 75 from Jinping district of Shantou city, where no e-waste recycling and dismantling activities existed. Structured interview questionnaires were administered to the pregnant women and umbilical cord blood (UCB) samples were collected after delivery. The UCB concentrations of lead, cadmium, chromium, and nickel were analyzed by graphite furnace atomic absorption spectrometry (GFAAS). Levels of UCB plasma 8-hydroxydeoxyguanosine (8-OHdG, a DNA oxidative damage biomarker) were determined by enzyme-linked immunosorbent assay. Results: Our results suggested that UCB lead and cadmium concentrations in neonates of Guiyu were significantly higher than those of Jinping (lead: median 110.45 ng/mL vs. 57.31 ng/mL; cadmium: median 2.50 ng/mL vs. 0.33 ng/mL, both P < 0.001). Parents' residence in Guiyu, and parents' work related to e-waste recycling were the risk factors associated with neonate's UCB lead and cadmium levels. No significant difference of UCB plasma 8-OHdG levels was found between Guiyu and the control area. After adjusting for potential confounders, cord plasma 8-OHdG concentrations (ng/mL) were positively associated with blood cadmium (β = 0.126 ng/mL, 95% CI: 0.055 to 0.198 ng/mL), chromium (β = 0.086 ng/mL, 95% CI: 0.014 to 0.158 ng/mL) and nickel (β = 0.215 ng/mL, 95% CI: 0.113 to 0.317 ng/mL) concentrations. Conclusions: The primitive e-waste recycling and dismantling activities may contribute to the elevated umbilical cord blood toxic heavy metal levels in neonates born in Guiyu. Exposures to cadmium, chromium and nickel were associated with increased oxidative DNA damage in neonates. - Highlights: • DNA oxidative damage levels (8-OHdG) in neonates from Guiyu were assessed.

  12. Associations of neonatal lead, cadmium, chromium and nickel co-exposure with DNA oxidative damage in an electronic waste recycling town

    International Nuclear Information System (INIS)

    Objective: This study aimed to evaluate the effects of toxic heavy metal co-exposure on DNA oxidative damage in neonates from a primitive e-waste recycling region, Guiyu town, China. Methods: Our participants included 201 pregnant women: 126 from Guiyu town and 75 from Jinping district of Shantou city, where no e-waste recycling and dismantling activities existed. Structured interview questionnaires were administered to the pregnant women and umbilical cord blood (UCB) samples were collected after delivery. The UCB concentrations of lead, cadmium, chromium, and nickel were analyzed by graphite furnace atomic absorption spectrometry (GFAAS). Levels of UCB plasma 8-hydroxydeoxyguanosine (8-OHdG, a DNA oxidative damage biomarker) were determined by enzyme-linked immunosorbent assay. Results: Our results suggested that UCB lead and cadmium concentrations in neonates of Guiyu were significantly higher than those of Jinping (lead: median 110.45 ng/mL vs. 57.31 ng/mL; cadmium: median 2.50 ng/mL vs. 0.33 ng/mL, both P < 0.001). Parents' residence in Guiyu, and parents' work related to e-waste recycling were the risk factors associated with neonate's UCB lead and cadmium levels. No significant difference of UCB plasma 8-OHdG levels was found between Guiyu and the control area. After adjusting for potential confounders, cord plasma 8-OHdG concentrations (ng/mL) were positively associated with blood cadmium (β = 0.126 ng/mL, 95% CI: 0.055 to 0.198 ng/mL), chromium (β = 0.086 ng/mL, 95% CI: 0.014 to 0.158 ng/mL) and nickel (β = 0.215 ng/mL, 95% CI: 0.113 to 0.317 ng/mL) concentrations. Conclusions: The primitive e-waste recycling and dismantling activities may contribute to the elevated umbilical cord blood toxic heavy metal levels in neonates born in Guiyu. Exposures to cadmium, chromium and nickel were associated with increased oxidative DNA damage in neonates. - Highlights: • DNA oxidative damage levels (8-OHdG) in neonates from Guiyu were assessed. • Neonatal lead

  13. Reduction of excess sludge production in sequencing batch reactor through incorporation of chlorine dioxide oxidation

    International Nuclear Information System (INIS)

    In this study, chlorine dioxide (ClO2) instead of chlorine (Cl2) was proposed to minimize the formation of chlorine-based by-products and was incorporated into a sequencing batch reactor (SBR) for excess sludge reduction. The results showed that the sludge disintegrability of ClO2 was excellent. The waste activated sludge at an initial concentration of 15 g MLSS/L was rapidly reduced by 36% using ClO2 doses of 10 mg ClO2/g dry sludge which was much lower than that obtained using Cl2 based on similar sludge reduction efficiency. Maximum sludge disintegration was achieved at 10 mg ClO2/g dry sludge for 40 min. ClO2 oxidation can be successfully incorporated into a SBR for excess sludge reduction without significantly harming the bioreactor performance. The incorporation of ClO2 oxidation resulted in a 58% reduction in excess sludge production, and the quality of the effluent was not significantly affected.

  14. Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II) Ions

    Science.gov (United States)

    Ibrahim, I; Lim, H. N; Huang, N. M; Pandikumar, A

    2016-01-01

    A photoelectrochemical (PEC) sensor with excellent sensitivity and detection toward copper (II) ions (Cu2+) was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO) nanocomposite on an indium tin oxide (ITO) surface, with triethanolamine (TEA) used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD) method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO) was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min) for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5–120 μM, with a limit of detection (LoD) of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection. PMID:27176635

  15. Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II) Ions.

    Science.gov (United States)

    Ibrahim, I; Lim, H N; Huang, N M; Pandikumar, A

    2016-01-01

    A photoelectrochemical (PEC) sensor with excellent sensitivity and detection toward copper (II) ions (Cu2+) was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO) nanocomposite on an indium tin oxide (ITO) surface, with triethanolamine (TEA) used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD) method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO) was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min) for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5-120 μM, with a limit of detection (LoD) of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection. PMID:27176635

  16. Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II Ions.

    Directory of Open Access Journals (Sweden)

    I Ibrahim

    Full Text Available A photoelectrochemical (PEC sensor with excellent sensitivity and detection toward copper (II ions (Cu2+ was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO nanocomposite on an indium tin oxide (ITO surface, with triethanolamine (TEA used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5-120 μM, with a limit of detection (LoD of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection.

  17. Cadmium-induced oxidative damage and protective effects of N-acetyl-L-cysteine against cadmium toxicity in Solanum nigrum L

    Energy Technology Data Exchange (ETDEWEB)

    Deng Xiaopeng; Xia Yan; Hu Wei [College of Life Sciences, Nanjing Agricultural University, Weigang 1, Nanjing 210095 (China); Zhang Hongxiao, E-mail: hxzhang@njau.edu.cn [College of Life Sciences, Nanjing Agricultural University, Weigang 1, Nanjing 210095 (China); Shen Zhenguo, E-mail: zgshen@njau.edu.cn [College of Life Sciences, Nanjing Agricultural University, Weigang 1, Nanjing 210095 (China)

    2010-08-15

    The effects of cadmium (Cd) on the accumulation of hydrogen peroxide (H{sub 2}O{sub 2}) and antioxidant enzyme activities in roots of Solanum nigrum L. and the role of N-acetyl-L-cysteine (NAC) as a cysteine (Cys) donor against Cd toxicity were investigated. Cd at 50 and 200 {mu}M significantly increased the contents of thiobarbituric acid-reactive substances (TBARS), the production of H{sub 2}O{sub 2} and superoxide anion (O{sub 2}{center_dot}{sup -}), and the activities of catalase, guaiacol peroxidase, ascorbate peroxidase, glutathione peroxidase (GSH-Px), glutathione reductase, and superoxide dismutase. Experiments with diphenylene iodonium as an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and NaN{sub 3} as an inhibitor of peroxidase showed that the major source of Cd-induced reactive oxygen species in the roots may include plasma membrane-bound NADPH oxidase and peroxidase. In addition, the effects of NAC on plant growth, antioxidant enzyme activity, and non-protein thiol content were analyzed. Under Cd stress, the addition of 500 {mu}M NAC decreased the contents of TBARS and production of H{sub 2}O{sub 2} and O{sub 2}{center_dot}{sup -}, but increased levels of Cys and reduced glutathione (GSH), phytochelatins, and activity of GSH-Px in roots. These results suggest that NAC could protect plants from oxidative stress damage, and this protection seems to be performed via increased GSH biosynthesis. Furthermore, NAC treatment also increased the contents of protein thiols in S. nigrum roots. By using size-exclusion chromatography, we found involvement of NAC in the Cd tolerance mechanism through increased biosynthesis of Cd-binding proteins.

  18. Effect of chronic exposure to cadmium on serum lipid, lipoprotein and oxidative stress indices in male rats

    Directory of Open Access Journals (Sweden)

    Samarghandian Saeed

    2015-09-01

    Full Text Available Cadmium (Cd is an environmental toxic metal implicated in lipid abnormalities. The present study was designed to elucidate the possible association between chronic exposure to Cd concentration and alterations in plasma lipid, lipoprotein, and oxidative stress indices in rats. Sixteen male rats were assigned to 2 groups of 8 rats each (test and control. The Cd-exposed group obtained drinking water containing cadmium chloride (CdCl2 in the concentration of 2.0 mg Cd/L in drinking water for 3 months. At the end of the experimental period, blood samples were obtained to determine the changes of serum triglycerides (TG, total cholesterol (TC, high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, reduced glutathione (GSH, malondialdehyde (MDA and also serum Cd contents. The results of the present study indicated that Cd administration significantly increased the serum levels of TG, TC, LDL-C, MDA and Cd with reduction in the HDL-C and GSH levels. In conclusion, evidence is presented that chronic exposure to low Cd concentration can adversely affect the lipid and lipoprotein profile via lipid peroxidation.

  19. Ion adsorption on oxides. Surface charge formation and cadmium binding on rutile and hematite.

    NARCIS (Netherlands)

    Fokkink, L.G.J.

    1987-01-01

    The adsorption of charge-determining (H +and OH -) and cadmium ions on rutile (TiO 2 ) and hematite (α-Fe 2 O 3 ) has been studied

  20. Oxygen-18 incorporation in NICI mass spectrometry: the role of O2, H2O and rhenium oxides in surface-assisted oxidation reactions

    Science.gov (United States)

    Stemmler, Elizabeth A.

    1995-04-01

    Surface-assisted oxidation reactions in the chemical ionization (CI) source have been studied using oxidation yield determinations and oxygen-18 incorporation measurements with 18O2 or H218O added to the negative ion chemical ionization buffer gas (N2 or Ar). Oxidation yield measurements show that O2, but not H2O, affects the oxidation yield. Using 18O2, 18O incorporation was found to be consistently lower in the ionized products of surface-assisted reactions compared with the products of gas-phase ion/molecule reactions. In addition, the degree of 18O incorporation was influenced by ion source temperature, with an increase in ion source temperature reducing the degree of incorporation. Although H2O has a negligible effect upon the efficiency of surface-assisted oxidation reactions, water-derived oxygen is efficiently incorporated by the products of surface-assisted oxidation reactions. In experiments with H218O + O2 mixtures a correlation between the 18O content of the oxidized products and the 18O content of filament-derived ReO4- was observed. This correlation, and the detection of rhenium oxides on ion source surfaces, suggest that filament-derived rhenium oxides may play a role in the activation of ion source surfaces towards the selective surface-catalyzed oxidation of aromatic hydrocarbons.

  1. Amelioration Effect of Zinc and Iron Supplementation on Selected Oxidative Stress Enzymes in Liver and Kidney of Cadmium-Treated Male Albino Rat

    OpenAIRE

    Jamakala, Obaiah; Rani, Usha A.

    2015-01-01

    Cadmium (Cd) is a highly toxic, nonessential heavy metal with many industrial uses that can contribute to a well-defined spectrum of diseases in animals as well as in humans. The present study examines the effect of zinc (Zn) and iron (Fe) supplementation on oxidative stress enzymes in Cd-treated rats. Wistar strain male albino rats were treated with cadmium chloride (CdCl2) at a dose of 1/10th LD50/48 h, that is, 22.5 mg/kg body weight for 7, 15, and 30 days (d) time intervals. The 15d Cd-tr...

  2. OXIDATIVE STRESS IN SHEEP INDUCED BY CADMIUM CHLORIDE TOXICITY, WITH THERAPEUTIC EFFECTS OF ALPHA LIPOIC ACID

    Directory of Open Access Journals (Sweden)

    Hussien Ali NAJI

    2015-09-01

    Full Text Available Cadmium (Cd is a heavy toxic metal, with harmful effects on animals and public health. Recently the risk of cadmium toxicity is substantially regarded; the environmental pollution is increased due to multi- uses of this element in various industries. This study was performed to clarify the effects of acute cadmium toxicity in sheep with trail of using alpha lipoic acid as an antioxidant therapeutic substance. Fifteen male lambs aged from 5-to-7 months were divided equally in to three groups, they were supplied with ordinary diet and provided with water ad-lib, the first group 1 was administered a single dose of CdCl2 3 mg/kg.bw subcutaneously (S/C, the second group 2 was injected with the same dose of CdCl2 and by the same route, and then simultaneously administered an alpha lipoic acid 50 mg/kg.bw intramuscularly, the later drug was repeated after 12 hours via the same route. The third group 3 was left as control and given normal saline (S/C. All animals were daily monitored and the clinical signs were recorded. The signs of cadmium toxicity appeared 18 hours post CdCl2 administration in the group 1; the signs were gradually increased in severity and multiple systems were involved included: digestive disturbances, cardiovascular and neurological dysfunctions, and locomotors abnormalities. Significant elevations in the body temperature, respiratory and heart rates were observed, deaths of 2 lambs were recorded 96 hours post CdCl2 injection. The group 2 showed mild clinical signs, and no death was occurred, moreover insignificant variations between clinical parameters in both groups 2 and 3 were recorded. Serum biochemical analysis revealed significant (P<0.05 increased of malondialdehyde (5.41 ± 0.282 μmol/L and glutathione (10.68 ± 0.38 μmol/L concentrations and marked elevation of serum catalase activity (103.85 ± 3.93 u/L was also observed in group I, whereas the last three parameters showed no significant differences between groups 2

  3. Incorporation of polyaniline nanofibres on graphene oxide by interfacial polymerization pathway for supercapacitor

    Science.gov (United States)

    Male, Umashankar; Srinivasan, Palaniappan; Singu, Bal Sydulu

    2015-09-01

    The aim of this work is to improve the supercapacitor performance of polyaniline (PANI). Polyaniline nano fibres are incorporated into graphene oxide (GO) layers by interfacial polymerization pathway, wherein PANI fibres are intercalated into GO layers and also cover the GO. PANI-GO hybrid composite is obtained in semi-crystalline form with good conductivity (1.7 S cm-1). The specific capacitance for PANI-GO (365 F g-1) is found to be higher than PANI (280 F g-1). At the energy density of 15 W h kg-1, the power density of PANI-GO (632 W kg-1) is higher than PANI (283 W kg-1).

  4. A Molecularly Imprinted Polymer with Incorporated Graphene Oxide for Electrochemical Determination of Quercetin

    Directory of Open Access Journals (Sweden)

    Xiwen He

    2013-04-01

    Full Text Available The molecularly imprinted polymer based on polypyrrole film with incorporated graphene oxide was fabricated and used for electrochemical determination of quercetin. The electrochemical behavior of quercetin on the modified electrode was studied in detail using differential pulse voltammetry. The oxidation peak current of quercetin in B-R buffer solution (pH = 3.5 at the modified electrode was regressed with the concentration in the range from 6.0 × 10−7 to 1.5 × 10−5 mol/L (r2 = 0.997 with a detection limit of 4.8 × 10−8 mol/L (S/N = 3. This electrode showed good stability and reproducibility. In the above mentioned range, rutin or morin which has similar structures and at the same concentration as quercetin did not interfere with the determination of quercetin. The applicability of the method for complex matrix analysis was also evaluated.

  5. Preparation of polyacrylnitrile (PAN)/ Manganese oxide based activated carbon nanofibers (ACNFs) for adsorption of Cadmium (II) from aqueous solution

    Science.gov (United States)

    Abdullah, N.; Yusof, N.; Jaafar, J.; Ismail, AF; Che Othman, F. E.; Hasbullah, H.; Salleh, W. N. W.; Misdan, N.

    2016-06-01

    In this work, activated carbon nanofibers (ACNFs) from precursor polyacrylnitrile (PAN) and manganese oxide (MnO2) were prepared via electrospinning process. The electrospun PAN/MnO2-based ACNFs were characterised in term of its morphological structure and specific surface area using SEM and BET analysis respectively. The comparative adsorption study of cadmium (II) ions from aqueous solution between the neat ACNFs, composite ACNFs and commercial granular activated carbon was also conducted. SEM analysis illustrated that composite ACNFs have more compact fibers with presence of MnO2 beads with smaller fiber diameter of 437.2 nm as compared to the neat ACNFs which is 575.5 nm. BET analysis elucidated specific surface area of ACNFs/MnO2 to be 67 m2/g. Under adsorption study, it was found out that Cd (II) removal by ACNFs/MnO2 was the highest (97%) followed by neat ACNFs (96%) and GAC (74%).

  6. Dependence of electrical and optical properties of sol-gel prepared undoped cadmium oxide thin films on annealing temperature

    International Nuclear Information System (INIS)

    The effect of the annealing temperature (T a) on the optical, electrical and structural properties of the undoped cadmium oxide (CdO) thin films obtained by the sol-gel method, using a simple precursor solution, was studied. All the CdO films annealed in the range from 200 to 450 deg. C are polycrystalline with (111) preferential orientation and present high optical transmission > 85% for wavelengths above 500 nm. The resistivity decreases as T a increases until it reaches a value of 6 x 10-4 Ω cm for T a 350 deg. C. For higher temperatures the resistivity experiences a slight increase. Images obtained by atomic force microscopy show an evident incremental change of the aggregate size (clusters of grains) as T a increases. The grain size also increases when T a increases as observed in data calculated from X-ray measurements

  7. Effects of cadmium-induced oxidative stress on growth and nitrogen assimilation in blackgram [Vigna mungo (L. Hepper

    Directory of Open Access Journals (Sweden)

    Mobin Mohammad

    2013-01-01

    Full Text Available Cadmium (Cd accumulation, oxidative damage, and nitrogen metabolism were studied in roots and leaves of 30-d-old blackgram plants [Vigna mungo (L. Hepper], grown in a mixture of soil and compost (3:1 with different Cd concentrations. Significant reductions in both root and shoot dry weight were noted. The concentration of Cd in roots and leaves increased with increasing Cd levels. The level of lipid peroxidation elevated with a consequent increase in H2O2 content under Cd stress in both plant organs. The activity of enzymes mediating the nitrogen assimilation in roots and leaves was greatly reduced in the presence of Cd, except glutamate dehydrogenase (GDH which showed a significant increase.

  8. Optical modeling and electrical properties of cadmium oxide nanofilms: Developing a meta–heuristic calculation process model

    Energy Technology Data Exchange (ETDEWEB)

    Abdolahzadeh Ziabari, Ali, E-mail: ali.abd.ziabari@gmail.com [Nano Research Lab, Lahijan Branch, Islamic Azad University, P.O. Box 1616, Lahijan (Iran, Islamic Republic of); Refahi Sheikhani, A. H. [Department of Applied Mathematics, Lahijan Branch, Islamic Azad University, Lahijan (Iran, Islamic Republic of); Nezafat, Reza Vatani [Department of Civil Engineering, Faculty of Technology, University of Guilan, Rasht (Iran, Islamic Republic of); Haghighidoust, Kasra Monsef [Department of Mechanical Engineering, Faculty of Technology, University of Guilan, Rasht (Iran, Islamic Republic of)

    2015-04-07

    Cadmium oxide thin films were deposited onto glass substrates by sol–gel dip-coating method and annealed in air. The normal incidence transmittance of the films was measured by a spectrophotometer. D.C electrical parameters such as carrier concentration and mobility were analyzed by Hall Effect measurements. A combination of Forouhi–Bloomer and standard Drude model was used to simulate the optical constants and thicknesses of the films from transmittance data. The transmittance spectra of the films in the visible domain of wavelengths were successfully fitted by using the result of a hybrid particle swarm optimization method and genetic algorithm. The simulated transmittance is in good accordance with the measured spectrum in the whole measurement wavelength range. The electrical parameters obtained from the optical simulation are well consistent with those measured electrically by Hall Effect measurements.

  9. Effect of pH of spray solution on the electrical properties of cadmium oxide thin films

    International Nuclear Information System (INIS)

    Highly conducting transparent cadmium oxide thin films were prepared by conventional spray pyrolysis technique on glass at 375 °C substrate temperature. The pH of the spray solution was varied by adding ammonia/hydrochloric acid in the spray solution. The XRD pattern showed cubic phase. A lowest resistivity of 9.9 × 10−4 Ω cm (with carrier concentration (n) = 5.1 × 1020 cm−3, mobility (µ)=12.4 cm2/Vs) is observed for pH ∼12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70 %. Thus, without any doping, the electrical conductivity of CdO films could be easily tuned by simply varying the pH of spray solution without compromising the transparency and keeping the other deposition parameters fixed

  10. Effect of pH of spray solution on the electrical properties of cadmium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hodlur, R. M.; Gunnagol, Raghu M.; Rabinal, M. K., E-mail: mkrabinal@yahoo.com [Department of Physics, Karnatak University, Dharwad - 580 003, Karnataka (India)

    2015-06-24

    Highly conducting transparent cadmium oxide thin films were prepared by conventional spray pyrolysis technique on glass at 375 °C substrate temperature. The pH of the spray solution was varied by adding ammonia/hydrochloric acid in the spray solution. The XRD pattern showed cubic phase. A lowest resistivity of 9.9 × 10{sup −4} Ω cm (with carrier concentration (n) = 5.1 × 10{sup 20} cm{sup −3}, mobility (µ)=12.4 cm{sup 2}/Vs) is observed for pH ∼12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70 %. Thus, without any doping, the electrical conductivity of CdO films could be easily tuned by simply varying the pH of spray solution without compromising the transparency and keeping the other deposition parameters fixed.

  11. Collagen incorporation within electrospun conduits reduces lipid oxidation and impacts conduit mechanics.

    Science.gov (United States)

    Birthare, Karamveer; Shojaee, Mozhgan; Jones, Carlos Gross; Brenner, James R; Bashur, Chris A

    2016-04-01

    Modulating the host response, including the accumulation of oxidized lipid species, is important for improving tissue engineered vascular graft (TEVG) viability. Accumulation of oxidized lipids promotes smooth muscle cell (SMC) hyper-proliferation and inhibits endothelial cell migration, which can lead to several of the current challenges for small-diameter TEVGs. Generating biomaterials that reduce lipid oxidation is important for graft survival and this assessment can provide a reliable correlation to clinical situations. In this study, we determined the collagen to poly(ε-caprolactone) (PCL) ratio required to limit the production of pro-inflammatory species, while maintaining the required mechanical strength for the graft. Electrospun conduits were prepared from 0%, 10%, and 25% blends of collagen/PCL (w/w) and implanted in the rat peritoneal cavity for four weeks. The results showed that adding collagen to the PCL conduits reduced the accumulation of oxidized lipid species within the implanted conduits. In addition, the ratio of collagen had a significant impact on the recruited cell phenotype and construct mechanics. All conduits exhibited greater than 44% yield strain and sufficient tensile strength post-implantation. In conclusion, these results demonstrate that incorporating collagen into synthetic electrospun scaffolds, both 10% and 25% blend conditions, appears to limit the pro-inflammatory characteristics after in vivo implantation. PMID:27099237

  12. Stability of uranium incorporated into Fe(hydr)oxides under fluctuating redox conditions

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, B.D.; Nico, P.S.; Fendorf, S.

    2009-04-01

    Reaction pathways resulting in uranium bearing solids that are stable (i.e., having limited solubility) under both aerobic and anaerobic conditions will limit dissolved concentrations and migration of this toxin. Here we examine the sorption mechanism and propensity for release of uranium reacted with Fe (hydr)oxides under cyclic oxidizing and reducing conditions. Upon reaction of ferrihydrite with Fe(II) under conditions where aqueous Ca-UO{sub 2}-CO{sub 3} species predominate (3 mM Ca and 3.8 mM CO{sub 3}-total), dissolved uranium concentrations decrease from 0.16 mM to below detection limit (BDL) after 5 to 15 d, depending on the Fe(II) concentration. In systems undergoing 3 successive redox cycles (15 d of reduction followed by 5 d of oxidation) and a pulsed decrease to 0.15 mM CO{sub 3}-total, dissolved uranium concentrations varied depending on the Fe(II) concentration during the initial and subsequent reduction phases - U concentrations resulting during the oxic 'rebound' varied inversely with the Fe(II) concentration during the reduction cycle. Uranium removed from solution remains in the oxidized form and is found both adsorbed on and incorporated into the structure of newly formed goethite and magnetite. Our 15 results reveal that the fate of uranium is dependent on anaerobic/aerobic conditions, aqueous uranium speciation, and the fate of iron.

  13. Oxidative stress induced by cadmium in the plasma, erythrocytes and lymphocytes of rats: Attenuation by grape seed proanthocyanidins.

    Science.gov (United States)

    Nazima, B; Manoharan, V; Miltonprabu, S

    2016-04-01

    The present study has been designed to investigate the ameliorative effect of grape seed proanthocyanidins (GSP) on cadmium (Cd)-induced oxidative damage in rat erythrocytes. Twenty four male Wistar rats were divided into four groups: control, GSP-treated group (100 mg kg(-1) body weight (BW)), Cd-treated group (cadmium chloride, 5 mg kg(-1) BW), and GSP + Cd-treated group in which GSP was orally pre-administered 90 min before Cd intoxication for 4 weeks. At the end of the experimental period, blood samples were collected by cardiac puncture and were processed for various biochemical estimations. The extent of oxidative damage in isolated rat erythrocyte membrane was assessed by measuring lipid peroxidation, enzymatic and non-enzymatic content, calcium ion (Ca(2+))/magnesium ion (Mg(2+))-ATPase and sodium ion (Na(+))/potassium ion (K(+))-ATPase activities, free iron, calcium, hydrogen peroxide (H2O2) concentration, and osmotic fragility. Our results unveiled that Cd intoxication significantly increased the erythrocyte lipid peroxidation markers and decreased the activity of enzymatic and non-enzymatic markers in erythrocytes. Conversely, GSP pretreatment significantly prevented the decrease in the activities of antioxidant enzymes and membrane-bound ATPases. GSP also restored the levels of iron, calcium, and H2O2 in Cd-treated rats. Conformational changes in erythrocytes of various groups were also determined using morphological and ultrastructural electron microscopic analysis. The findings of our study clearly revealed that GSP affords superior protection against Cd-induced reactive oxygen species generation, lipid peroxidation, and free radical generation in Cd-treated rats, which presumably reflects the ability of this flavonoid to protect erythrocytes and lymphocytes of rats from the toxic effects of Cd. PMID:26089033

  14. Towards a Predictive Thermodynamic Model of Oxidation States of Uranium Incorporated in Fe (hydr) oxides

    Energy Technology Data Exchange (ETDEWEB)

    Bagus, Paul S. [Univ. of North Texas, Denton, TX (United States)

    2013-01-01

    The theoretical research in this project has been directed toward the interpretation of core-level spectroscopies for systems relevant to the project. For the initial efforts, the focus of our theoretical simulations has been the interpretation of laboratory and synchrotron X-Ray Photoemission Spectra, XPS. In more recent efforts, an increasing emphasis has been placed on developing transparent understandings of X-Ray Adsorption Spectra, XAS . For the XAS, the principal concern is for the near-edge features, either just below or just above, an ionization limit or edge, which are described as Near-Edge X-Ray Adsorption Fine Structure, NEXAFS. In particular, a priority has involved the analysis and interpretation of XPS and NEXAFS spectra, especially of Fe and U systems, as measured by our PNNL collaborators. The overall objective of our theoretical studies is to establish connections between features of the spectra and their origin in the electronic structure of the materials. The efforts for the analysis of XPS have been reviewed in a paper by the PI, C. J. Nelin, and E. S. Ilton from PNNL on “The interpretation of XPS spectra: Insights into materials properties”, Surf. Sci. Reports, 68, 273 (2013). Two materials properties of special interest have been the degree of ionicity and the character of the covalent bonding in a range of oxides formed with transition metal, lanthanide, and actinide cations. Since the systems treated have electrons in open shells, it has been necessary to determine the energetics and the character of the angular momentum coupling of the open shell electrons. In particular, we have established methods for the treatment of the “intermediate coupling” which arises when the system is between the limit of Russell-Saunders multiplets, and the limit of j-j coupling where the spin-orbit splittings of single electrons dominate. A recent paper by the PI, and M. J. Sassi, and K. M. Rosso, (both at PNNL) “Intermediate Coupling For Core

  15. Zinc and cadmium monosalicylates

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K. (Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR))

    1984-06-01

    Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC/sub 6/H/sub 4/COOH (H/sub 2/Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC/sub 6/H/sub 4/COO) and products of their thermal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure.

  16. Cadmium chloride induced cell injury through oxidative stress%镉通过氧化应激机制诱导LLC-PK1细胞损伤

    Institute of Scientific and Technical Information of China (English)

    方鑫; 李海玲; 安彩艳

    2014-01-01

    目的:探讨镉诱导猪肾近曲小管上皮细胞(LLC-PK1)毒性及氧化应激在其中的作用。方法用不同浓度的氯化镉刺激细胞9h和25μmol/L的氯化镉刺激细胞不同时间,采用Formazan 分析细胞存活率反映镉对细胞的损伤程度;以还原型谷胱甘肽(GSH)为靶点,影响GSH浓度的两个试剂BSO和NAC,观察镉诱导细胞损伤中氧化应激的作用。结果随着氯化镉染毒时间延长,细胞存活率下降,同样,随着剂量的增加,细胞的存活率逐渐也下降。同时BSO加重镉诱导的细胞损伤,NAC完全抑制镉诱导的细胞损伤。结论氯化镉对LLC- PK1细胞具有明显的毒性,细胞损伤是通过氧化应激介导,且与细胞内的谷胱甘肽的水平有着密切关系。%Objective To investigate the possible mechanisms of cadmium chloride-induced LLC-PK1 cell toxicity and the role of oxidative stress during the progress. Methods LLC-PK1 cells were treated with different concentrations of cadmium chloride for 9h,and different times at the same dose of cadmium chloride (25μmol/L), respectively.Formazan was used to analyze the cells viability.GSH was taken as a target,and the role of oxidative stress in the progress of cadmium chloride-induced cell injury was assessed by BSO and NAC. Results With the increasing of treatment time and cadmium concentration,Cadmium-induced cell toxicity became more serious and the viability of cells decreased.The cell susceptibility to cadmium chloride could be substantially altered by glutathione (GSH)-modulating agents.Depletion of GSH with BSO increased, whereas supply of cells with NAC decreased subsequent cell injury. Conclusion Cadmium chloride induced cell injury through oxidative stress,which was closely associated with the expression level of intracellular GSH.

  17. Retardation of lipid oxidation using gelatin film incorporated with longan seed extract compared with BHT.

    Science.gov (United States)

    Sai-Ut, Samart; Benjakul, Soottawat; Rawdkuen, Saroat

    2015-09-01

    The aim of the present work was to apply the gelatin films with different levels of longan seed extract (LS) or butylated hydroxytoluene (BHT) on retardation of lipid oxidation in soybean oil. The films incorporated with various concentrations of aqueous LS (0, 50, 100, 300, and 500 ppm) or BHT (50, and 100 ppm) were developed. The films had transmittance percentages of 60-80 % at 570 nm and showed good light barrier properties when the concentration of LS or BHT increased. About 97 % protein solubility and 41 to 54 % water solubility were obtained for the developed films. Antioxidative activity of gelatin films incorporated with LS increased markedly with increasing storage time as indicated by the increase in DPPH radical scavenging activity (41-50 %) (P  0.05). According to these findings, gelatin film incorporated with longan seed extract or BHT could be used as a tool to prolong the shelf-life of oily foods. PMID:26344999

  18. Interplay between mass-impurity and vacancy phonon scattering effects on the thermal conductivity of doped cadmium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, Brian F. [Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Sachet, Edward; Maria, Jon-Paul [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Hopkins, Patrick E., E-mail: phopkins@virginia.edu [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States)

    2016-01-11

    Understanding the impact and complex interaction of thermal carrier scattering centers in functional oxide systems is critical to their progress and application. In this work, we study the interplay among electron and phonon thermal transport, mass-impurity scattering, and phonon-vacancy interactions on the thermal conductivity of cadmium oxide. We use time domain thermoreflectance to measure the thermal conductivity of a set of CdO thin films doped with Dy up to the saturation limit. Using measurements at room temperature and 80 K, our results suggest that the enhancement in thermal conductivity at low Dy concentrations is dominated by an increase in the electron mobility due to a decrease in oxygen vacancy concentration. Furthermore, we find that at intermediate doping concentrations, the subsequent decrease in thermal conductivity can be ascribed to a large reduction in phononic thermal transport due to both point defect and cation-vacancy scattering. With these results, we gain insight into the complex dynamics driving phonon scattering and resulting thermal transport in functional oxides.

  19. Effect of the oxygen-containing functional group of graphene oxide on the aqueous cadmium ions removal

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Yu [College of Water Sciences, Beijing Normal University, Beijing 100875 (China); Bian, Zhao-Yong, E-mail: bian@bnu.edu.cn [College of Water Sciences, Beijing Normal University, Beijing 100875 (China); Zhang, Jun-Xiao; Ding, Ai-Zhong [College of Water Sciences, Beijing Normal University, Beijing 100875 (China); Liu, Shao-Lei [College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083 (China); Wang, Hui, E-mail: wanghui@bjfu.edu.cn [College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083 (China)

    2015-02-28

    Highlights: • The role of oxygen-containing function groups of graphene oxide on the Cd(II) sorption was investigated. • The changes of carbon and oxygen state during the interaction of Cd(II) and graphene oxide were monitored using XPS. • The coordination effect of the oxygen function groups of graphene oxide should be in favor to the Cd(II) removal. • The properties of simple component and plain structure of graphene oxide greatly exclude the interference of other factors. - Abstract: The adsorption process of graphene oxide (GO) with oxygen-containing functional groups towards cadmium ions was investigated. GO synthesized from graphite by using the modified Hummers method was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS). The oxygen-containing groups on the surfaces of GO played an important role in Cd(II) ion adsorption onto GO. The results of batch experiments indicated that maximal adsorption, which was found to be 23.9 mg/g, could be achieved over the broad pH range of 6.0–7.0. Adsorption isotherms were better fitted by Freundlich model than by Langmuir model and kinetic studies suggested that adsorption was controlled by chemical adsorption. According to FT-IR and XPS analyses of before and after Cd(II) adsorption on GO, electrostatic attraction and cation exchange between Cd(II) and O-containing functional groups on GO were the dominant mechanisms responsible for Cd(II) sorption.

  20. Effect of titanium oxide nanoparticle incorporation into nm thick coatings deposited using an atmospheric pressure plasma.

    Science.gov (United States)

    Denis, Dowling P; Barry, Twomey; Gerry, Byrne

    2010-04-01

    This study reports on the use of an atmospheric plasma technique to incorporate metal oxide nanoparticles into nm thick siloxane coatings. Titanium dioxide (TiO2) particles with diameters of 30-80 nm, were mixed with a number of different siloxanes-polydimethylsiloxane, hexamethyldisiloxane and tetraethylorthosilicate (TEOS). The TiO2/TEOS mixture was found to give the most stable suspension, possibly due to the higher surface tension of TEOS compared with the other siloxanes. TiO2/TEOS mixtures with 2 to 10% by weight of the metal oxide were prepared and were then nebulised into a helium/oxygen atmospheric plasma. Polyethylene terepthalate (PET) and silicon wafer substrates were passed through this plasma using a reel-to-reel substrate manipulation system. SEM combined with EDX was used to examine the distribution of the metal oxide particles in the resultant coatings. The TEOS coating thickness without TiO2 addition was 9 nm. The composite coating consisted of a relatively homogeneous distribution of small agglomerates of the TiO2 nanoparticles in TEOS. A linear increase in the titanium surface concentration was observed with increase in the quantity of TiO2 added into the siloxane precursor. The chemical functionality of the siloxane coating was examined using FTIR spectroscopy and no significant spectrum differences was observed with the incorporation of the different concentrations of TiO2 into the polymer. There were also no changes observed in coating surface energy with TiO2 incorporation. Coating morphology was examined using optical profilometry and surface roughness (Ra) values increased from typical values of 0.8 nm for the TEOS coating to 4.1 nm for the TiO2/TEOS coating. The adhesion of the deposited coatings was compared using fragmentation tests. These were carried out through uniaxial tensile loading. The coating cracking pattern after applied strain of 20% was not observed to change significantly with the addition of TiO2 into the siloxane. PMID

  1. Enhanced mechanical behaviour of lead zirconate titanate piezoelectric composites incorporating zinc oxide nanowhiskers

    Institute of Scientific and Technical Information of China (English)

    Lin Hai-Bo; Cao Mao-Sheng; Yuan Jie; Wang Da-Wei; Zhao Quan-Liang; Wang Fu-Chi

    2008-01-01

    This paper reports that the lead zirconate titanate (PZT) piezoelectric composites incorporating zinc oxide nanowhiskers (ZnOw) were prepared by the conventional solid state processing.The whisker-dispersed PZT composites (PZT/ZnOw) presented a significant enhancement in the mechanical properties such as Young's modulus,tensile strength and compressive strength.Especially,the compressive strength increased from 153 MPa for the PZT to 228 MPa for thc PZT/ZnOw composites.The reinforcement mechanism in strength of the composites was discussed.The mechanical quality factors of the PZT/ZnOw composites increased considerably,while the piezoelectric constants and electromechanical coupling coefficient decreased slightly.The composites with good electrical and excellent mechanical properties are promising for further applications.

  2. Single pot synthesis of pyridine-N-oxide based polymeric complexes of cadmium and manganese: Crystal structure and luminescence property

    Science.gov (United States)

    Mondal, Sandip; Guha, Averi; Suresh, Eringathodi; Jana, Atish Dipankar; Banerjee, Arpita

    2012-12-01

    Two new polymeric complexes of cadmium(II) and manganese(II) with Pyridine-N-oxide (pyo) mediated by thiocyanate and dicyanamide (dca) anions have been synthesized and characterized by X-ray single crystal structure analysis. The structural analyses reveal that complexes [Cd(pyo)2(SCN)2]n (1) and [Mn(pyo)2(dca)2]n (2) [where, pyo = pyridine-N-oxide; dca = dicyanamide] are 2D coordination polymers. In complex 1 hexa-coordinated Cd(II) centers posses distorted octahedral coordination environments. Each Cd(II) is coordinated by four SCN- in end to end fashion forming a zigzag chain and two pyo monodentate ligands bridge two adjacent Cd(II) centers leading to a two-dimensional sheet structure. In complex 2 hexa-coordinated Mn(II) centers posses octahedral coordination environments. The coordination polymer constitute a 2D polymeric sheet and has a (4, 4) grid network architecture Successive stacking of coordination polymeric sheets are enforced by inter layer OH⋯O and OH⋯N hydrogen bonding. The luminescence properties of these two polynuclear complexes in solid state were studied and complex 1 exhibits higher luminescence intensity than 2.

  3. Sol-Gel Synthesis and Antioxidant Properties of Yttrium Oxide Nanocrystallites Incorporating P-123

    Directory of Open Access Journals (Sweden)

    Rebeca Mellado-Vázquez

    2014-09-01

    Full Text Available Yttrium oxide (Y2O3 nanocrystallites were synthesized by mean of a sol-gel method using two different precursors. Raw materials used were yttrium nitrate and yttrium chloride, in methanol. In order to promote oxygen vacancies, P-123 poloxamer was incorporated. Synthesized systems were heat-treated at temperatures from 700 °C to 900 °C. Systems at 900 °C were prepared in the presence and absence of P-123 using different molar ratios (P-123:Y = 1:1 and 2:1. Fourier transform infrared spectroscopy (FTIR results revealed a characteristic absorption band of Y–O vibrations typical of Y2O3 matrix. The structural phase was analyzed by X-ray diffraction (XRD, showing the characteristic cubic phase in all systems. The diffraction peak that presented the major intensity corresponded to the sample prepared from yttrium chloride incorporating P-123 in a molar ratio of P-123:Y = 2:1 at 900 °C. Crystallites sizes were determined by Scherrer equation as between 21 nm and 32 nm. Antioxidant properties were estimated by 2,2-diphenyl-1-picrylhydrazyl (DPPH• assays; the results are discussed.

  4. Zinc oxide nanoparticles with incorporated silver: Structural, morphological, optical and vibrational properties

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera, Edgar, E-mail: edemova@ing.uchile.cl [Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile); Rojas-Michea, Carolina, E-mail: rojasmichea@gmail.com [Departamento de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Tupper 2007, Santiago (Chile); Morel, Mauricio, E-mail: mmorel@ing.uchile.cl [Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile); Gracia, Francisco, E-mail: Fgracia@ing.uchile.cl [Departamento de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Tupper 2007, Santiago (Chile); Fuenzalida, Víctor, E-mail: vfuenzal@ing.uchile.cl [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Blanco Encalada 2008, Santiago (Chile); Zárate, Ramón A., E-mail: rzarate@ucn.cl [Departamento de Física, Facultad de Ciencias, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile)

    2015-08-30

    Graphical abstract: Local vibrational modes of ZnO:Ag nanoparticles. - Highlights: • Formation of Ag biphases is observed when the Ag content increases. • The SPR property has been monitored in the UV–visible regime. • PL emission of ZnO:Ag nanoparticles are associated to structural defects. • A new local vibrational mode induced by Ag content were observed in the Raman spectra. - Abstract: Zinc oxide nanoparticles with different amounts of incorporated silver (ZnO:Ag; 0.6, 3, 6, and 9 at.% Ag) have been successfully synthesized by a simple sol gel method. The effect of Ag content on the properties of ZnO nanoparticles have been studied by various characterization techniques. The results from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS) suggest that elemental silver is present as a second phase. The UV–visible absorption and photoluminescence (PL) properties of the samples were also studied. PL data at room temperature reveals a strong blue emission. In addition, Raman spectroscopy results indicate a very strong A{sub 1}(LO) mode resulting from oxygen vacancies and zinc interstitials. A new local vibrational mode (LVM) at 480 cm{sup −1} induced by silver can also be observed in the Raman spectra, suggesting silver incorporation into the ZnO lattice compensating the Zn vacancies, which is consistent with the XRD results.

  5. Zinc oxide nanoparticles with incorporated silver: Structural, morphological, optical and vibrational properties

    International Nuclear Information System (INIS)

    Graphical abstract: Local vibrational modes of ZnO:Ag nanoparticles. - Highlights: • Formation of Ag biphases is observed when the Ag content increases. • The SPR property has been monitored in the UV–visible regime. • PL emission of ZnO:Ag nanoparticles are associated to structural defects. • A new local vibrational mode induced by Ag content were observed in the Raman spectra. - Abstract: Zinc oxide nanoparticles with different amounts of incorporated silver (ZnO:Ag; 0.6, 3, 6, and 9 at.% Ag) have been successfully synthesized by a simple sol gel method. The effect of Ag content on the properties of ZnO nanoparticles have been studied by various characterization techniques. The results from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS) suggest that elemental silver is present as a second phase. The UV–visible absorption and photoluminescence (PL) properties of the samples were also studied. PL data at room temperature reveals a strong blue emission. In addition, Raman spectroscopy results indicate a very strong A1(LO) mode resulting from oxygen vacancies and zinc interstitials. A new local vibrational mode (LVM) at 480 cm−1 induced by silver can also be observed in the Raman spectra, suggesting silver incorporation into the ZnO lattice compensating the Zn vacancies, which is consistent with the XRD results

  6. Laser ablation synthesis of lanthanide oxide cluster ions incorporating a heterovalent metal

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J.K. [Oak Ridge National Lab., TN (United States)

    1996-01-11

    Lanthanide (Ln) oxide cluster ions produced directly by excimer laser ablation of oxalates into vacuum were investigated by time-of-flight mass spectrometry. Whereas previous studies in our laboratory identified pure Ln{sub m}O{sub n}{sup +} and mixed Ln{sub m1}Ln`{sub m2}O{sub n}{sup +}, the present work focused on analogous clusters incorporating an alkaline earth (A) or transition (T) metal: [C@Ln{sub m}O{sub n}.@pAO]C{sup +} and [C@Ln{sub m}O{sub n}.TO{sub 2}]C{sup +} (Ln = La, Tb, Ho or Yb; A = Ca or Sr; T = Ta, Zr, or Hf). The formation of atomically combined clusters from physical mixtures of a solid lanthanide oxalate with a heterovalent metal oxide supports gas-phase coalescence as the dominant formation mechanism (vs direct cluster ejection). The stoichiometries and abundance distributions of the bimetallic oxide cluster ions are interpreted in the context of their chemical and structural constitutions. Ion abundance maxima for [C@LnO.3AO]C{sup +} are consistent with an ionically bonded cuboid microlattice; this cubic structure type may also pertain to related binary Ln{sub m}O{sub n}{sup +}. Distinctive abundances (stabilities) of such compositions as [C@Ln{sub 3}O{sub 4}.@2AO]C{sup +} and [C@Ln{sub 5}O{sub 7}.@AO]C{sup +} suggest similar cuboid structures there. 29 refs., 4 figs., 1 tab.

  7. Gently reduced graphene oxide incorporated into cobalt oxalate rods as bifunctional oxygen electrocatalyst

    International Nuclear Information System (INIS)

    Graphical abstract: - Abstract: Water-oxygen electrochemistry is at the heart of key renewable energy technologies (fuel cells, electrolyzers, and metal-air batteries) due to the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Although much effort has been devoted to the development of improved bifunctional electrocatalysts, an inexpensive, highly active oxygen electrocatalyst, however, remains to be a challenge. In this paper, we present a facile and robust method to create gently reduced graphene oxide incorporated into cobalt oxalate microstructures (CoC2O4/gRGO) and demonstrate its excellent and stable electrocatalytic activity in both OER and ORR, arising from the inherent properties of the components and their physicochemical interaction. Our synthesis technique also explores a single pot method to partially reduce graphene oxide and form CoC2O4 structures while maintaining the solution processability of reduced graphene oxide. While the OER activity of CoC2O4/gRGO is exclusively due to CoC2O4, which transformed into OER-active Co species, the combination with gRGO significantly improves OER stability. On the other hand, CoC2O4/gRGO exhibits synergistic effect towards ORR, via a quasi-four-electron pathway, leading to a slightly higher ORR limiting current than Pt/C. Remarkably, gRGO offers dual functionality, contributing to ORR activity via the N-functional groups and also enhancing OER stability through the gRGO coating around CoC2O4 structures. Our results suggest a new class of metal-carbon composite that has the potential to be alternative bifunctional catalysts for regenerative fuel cells and metal-air batteries

  8. Oxidative stress parameters induced by exposure to either cadmium or 17β-estradiol on Mytilus galloprovincialis hemocytes. The role of signaling molecules

    Energy Technology Data Exchange (ETDEWEB)

    Koutsogiannaki, Sophia [Laboratory of Animal Physiology, Zoology Department, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Franzellitti, Silvia [University of Bologna, Interdepartment Centre for Environmental Science Research, via S. Alberto 163, 48123 Ravenna (Italy); Fabbri, Elena [University of Bologna, Interdepartment Centre for Environmental Science Research, via S. Alberto 163, 48123 Ravenna (Italy); University of Bologna, Department of Biological, Geological, and Environmental Sciences, via Selmi 3, 40100 Bologna (Italy); Kaloyianni, Martha, E-mail: kaloyian@bio.auth.gr [Laboratory of Animal Physiology, Zoology Department, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2014-01-15

    Highlights: •Oxidative parameters in Mytilus galloprovincialis hemocytes were measured. •Comparison between cadmium and 17β-estradiol cytotoxicity is discussed. •NHE, PKC, PI3-K, NADPH oxidase, NO synthase, JNK involvement was observed. •Protective role of cAMP is suggested. •Signaling molecules studied could constitute novel biomarkers. -- Abstract: The aim of the present study was to determine and compare the possible effects of exposure to an estrogen, 17β-estradiol and to a metal, cadmium on oxidative parameters of Mytilus galloprovincialis hemocytes and to elucidate the signaling pathways that probably mediate the studied effects exerted by these two chemicals. In addition, it was of interest to investigate if the studied parameters could constitute biomarkers for aquatic pollution monitoring. Our results suggest that micromolar concentrations of either cadmium or 17β-estradiol affected the redox status of mussels by modulating oxidative parameters and antioxidant enzymes gene expression in mussel M. galloprovincialis hemocytes. In particular, our results showed that treatment of hemocytes with either 5 μM of cadmium chloride or with 25 nM of 17β-estradiol for 30 min caused significant increased ROS production; this led to oxidative damage exemplified by significant increased DNA damage, protein carbonylation and lipid peroxidation, as well as increased mRNA levels of the antioxidant enzymes catalase (CAT), superoxide dismoutase (SOD) and glutathione S-transferase (GST). Furthermore, our results suggest that either cadmium or 17β-estradiol signal is mediated either through one of the already known pathways initiated by photatidyl-inositol 3-kinase (PI3 K) and reaching Na{sup +}/H{sup +} exchanger (NHE) probably through protein kinase C (PKC) or a kinase-mediated signaling pathway that involves in most of the cases NHE, PKC, Ca{sup 2+}-dependent PKC isoforms, PI3-K, NADPH oxidase, nitric oxide (NO) synthase, c-Jun N-terminal kinase (JNK) and

  9. Effects of cadmium stress on growth and anti-oxidative systems in Achnatherum inebrians symbiotic with Neotyphodium gansuense

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xingxu [Key Laboratory of Grassland Agro-Ecosystems, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730000, Gansu (China); Li Chunjie, E-mail: chunjie@lzu.edu.cn [Key Laboratory of Grassland Agro-Ecosystems, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730000, Gansu (China); Nan Zhibiao [Key Laboratory of Grassland Agro-Ecosystems, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730000, Gansu (China)

    2010-03-15

    The effects of cadmium on biomass production and growth parameters of drunken horse grass (Achnatherum inebrians) over an 8-week period were determined in a controlled-environment experiment. Changes were determined for relative water content, anti-oxidative enzymes (i.e., catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX)) and for H{sub 2}O{sub 2} content, as well as levels of proline, malondialdehyde (MDA), and chlorophylls 'a' and 'b' present within leaves infected with Neotyphodium gansuense vs. non-infected controls. Observations began 4 weeks after addition of CdCl{sub 2} (0, 50, 100 and 200 {mu}M) to the nutrient solution. Under high concentrations (100 and 200 {mu}M) of CdCl{sub 2}, endophyte-infected plants produced more biomass and had higher values for plant height and tiller number compared to non-infected controls, but there was no significant difference (P > 0.05) under 0 and 50 {mu}M CdCl{sub 2}. Anti-oxidative enzyme activities, H{sub 2}O{sub 2} concentration, and chlorophylls 'a' and 'b' levels increased, but proline and malondialdehyde content declined in the infected plants vs. non-infected plants under high (100 and 200 {mu}M) concentrations of CdCl{sub 2}. There was no significant difference (P > 0.05) under 0 and 50 {mu}M CdCl{sub 2}. Endophyte infection was concluded to be of benefit to the growth and anti-oxidative mechanisms within A. inebrians under high concentrations exposures to CdCl{sub 2}.

  10. Role of Nrf2 antioxidant defense in mitigating cadmium-induced oxidative stress in the olfactory system of zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lu; Gallagher, Evan P., E-mail: evang3@uw.edu

    2013-01-15

    Exposure to trace metals can disrupt olfactory function in fish leading to a loss of behaviors critical to survival. Cadmium (Cd) is an olfactory toxicant that elicits cellular oxidative stress as a mechanism of toxicity while also inducing protective cellular antioxidant genes via activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, the molecular mechanisms of Cd-induced olfactory injury have not been characterized. In the present study, we investigated the role of the Nrf2-mediated antioxidant defense pathway in protecting against Cd-induced olfactory injury in zebrafish. A dose-dependent induction of Nrf2-regulated antioxidant genes associated with cellular responses to oxidative stress was observed in the olfactory system of adult zebrafish following 24 h Cd exposure. Zebrafish larvae exposed to Cd for 3 h showed increased glutathione S-transferase pi (gst pi), glutamate–cysteine ligase catalytic subunit (gclc), heme oxygenase 1 (hmox1) and peroxiredoxin 1 (prdx1) mRNA levels indicative of Nrf2 activation, and which were blocked by morpholino-mediated Nrf2 knockdown. The inhibition of antioxidant gene induction in Cd-exposed Nrf2 morphants was associated with disruption of olfactory driven behaviors, increased cell death and loss of olfactory sensory neurons (OSNs). Nrf2 morphants also exhibited a downregulation of OSN-specific genes after Cd exposure. Pre-incubation of embryos with sulforaphane (SFN) partially protected against Cd-induced olfactory tissue damage. Collectively, our results indicate that oxidative stress is an important mechanism of Cd-mediated injury in the zebrafish olfactory system. Moreover, the Nrf2 pathway plays a protective role against cellular oxidative damage and is important in maintaining zebrafish olfactory function. -- Highlights: ► Oxidative stress is an important mechanism of Cd-mediated olfactory injury. ► Cd induces antioxidant gene expression in the zebrafish olfactory system. ► The

  11. Cadmium carcinogenesis

    International Nuclear Information System (INIS)

    Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis

  12. Optical and electrical characterization of fluorine doped cadmium oxide thin films prepared by the sol-gel method

    International Nuclear Information System (INIS)

    Highly transparent and conducting fluorine (F) doped cadmium oxide (CdO) thin films were deposited on glass slides by the sol-gel method. The films were doped by the addition of ammonium fluoride to the precursor solution whose optimum concentration was determined. The films were fired in an open atmosphere at 350 deg. C and after that, exposed to annealing treatments in different atmospheres (N2, N2/H2 mixture and Ar) at the same temperature. The films were characterized by ultraviolet-visible spectroscopy, X-ray diffraction and scanning electron microscopy. The resistivity was determined by the four probes method and current-voltage measurements in accordance with the standard Van der Pauw configuration. The CdO:F thin films obtained, showed high polycrystalline quality and high transmission in the visible region (≥ 90%), shifting towards the blue region of the absorption edge as the fluorine concentration in the precursor solution was increased from 0 to 30 at.%. The lowest resistivity values were reached for the samples with F content higher or equal to 5% and annealed in either N2 or a 96/4 N2/H2 gas mixture. Our resistivity value reached in the CdO:F layers was 4.5 x 10-4 Ω cm (20 Ω/square)

  13. Oxidative responsiveness to multiple stressors in the key Antarctic species, Adamussium colbecki: Interactions between temperature, acidification and cadmium exposure.

    Science.gov (United States)

    Benedetti, Maura; Lanzoni, Ilaria; Nardi, Alessandro; d'Errico, Giuseppe; Di Carlo, Marta; Fattorini, Daniele; Nigro, Marco; Regoli, Francesco

    2016-10-01

    High-latitude marine ecosystems are ranked to be among the most sensitive regions to climate change since highly stenothermal and specially adapted organisms might be seriously affected by global warming and ocean acidification. The present investigation was aimed to provide new insights on the sensitivity to such environmental stressors in the key Antarctic species, Adamussium colbecki, focussing also on their synergistic effects with cadmium exposure, naturally abundant in this area for upwelling phenomena. Scallops were exposed for 2 weeks to various combinations of Cd (0 and 40 μgL-1), pH (8.05 and 7.60) and temperature (-1 and +1 °C). Beside Cd bioaccumulation, a wide panel of early warning biomarkers were analysed in digestive glands and gills including levels of metallothioneins, individual antioxidants and total oxyradical scavenging capacity, onset of oxidative cell damage like lipid peroxidation, lysosomal stability, DNA integrity and peroxisomal proliferation. Results indicated reciprocal interactions between multiple stressors and their elaboration by a quantitative hazard model based on the relevance and magnitude of effects, highlighted a different sensitivity of analysed tissues. Due to cellular adaptations to high basal Cd content, digestive gland appeared more tolerant toward other prooxidant stressors, but sensitive to variations of the metal. On the other hand, gills were more affected by various combinations of stressors occurring at higher temperature.

  14. Liver Toxicity of Cadmium Telluride Quantum Dots (CdTe QDs Due to Oxidative Stress in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Ting Zhang

    2015-09-01

    Full Text Available With the applications of quantum dots (QDs expanding, many studies have described the potential adverse effects of QDs, yet little attention has been paid to potential toxicity of QDs in the liver. The aim of this study was to investigate the effects of cadmium telluride (CdTe QDs in mice and murine hepatoma cells alpha mouse liver 12 (AML 12. CdTe QDs administration significantly increased the level of lipid peroxides marker malondialdehyde (MDA in the livers of treated mice. Furthermore, CdTe QDs caused cytotoxicity in AML 12 cells in a dose- and time-dependent manner, which was likely mediated through the generation of reactive oxygen species (ROS and the induction of apoptosis. An increase in ROS generation with a concomitant increase in the gene expression of the tumor suppressor gene p53, the pro-apoptotic gene Bcl-2 and a decrease in the anti-apoptosis gene Bax, suggested that a mitochondria mediated pathway was involved in CdTe QDs’ induced apoptosis. Finally, we showed that NF-E2-related factor 2 (Nrf2 deficiency blocked induced oxidative stress to protect cells from injury induced by CdTe QDs. These findings provide insights into the regulatory mechanisms involved in the activation of Nrf2 signaling that confers protection against CdTe QDs-induced apoptosis in hepatocytes.

  15. Effect of the oxygen-containing functional group of graphene oxide on the aqueous cadmium ions removal

    Science.gov (United States)

    Bian, Yu; Bian, Zhao-Yong; Zhang, Jun-Xiao; Ding, Ai-Zhong; Liu, Shao-Lei; Wang, Hui

    2015-02-01

    The adsorption process of graphene oxide (GO) with oxygen-containing functional groups towards cadmium ions was investigated. GO synthesized from graphite by using the modified Hummers method was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS). The oxygen-containing groups on the surfaces of GO played an important role in Cd(II) ion adsorption onto GO. The results of batch experiments indicated that maximal adsorption, which was found to be 23.9 mg/g, could be achieved over the broad pH range of 6.0-7.0. Adsorption isotherms were better fitted by Freundlich model than by Langmuir model and kinetic studies suggested that adsorption was controlled by chemical adsorption. According to FT-IR and XPS analyses of before and after Cd(II) adsorption on GO, electrostatic attraction and cation exchange between Cd(II) and O-containing functional groups on GO were the dominant mechanisms responsible for Cd(II) sorption.

  16. Structural Basis of Uranium Incorporation In Natural Iron (Oxyhydr)oxides

    Science.gov (United States)

    Michel, F. M.; Massey, M. S.; Lezama-Pacheco, J. S.; Brown, G. E.; Fendorf, S. E.; Bargar, J.

    2009-12-01

    The development of in situ remediation strategies for uranium-contaminated groundwater at US Department of Energy (DOE) sites such as Oak Ridge, Tennessee, and Rifle, Colorado is a major DOE objective. The long-term performance, cost, and public acceptance of these approaches depend on a fundamental understanding of molecular-scale biogeochemical processes that operate in the subsurface to control the retention and stability of uranium. One important process is the interaction of U with the metastable and highly reactive solid ferrihydrite (a poorly crystalline Fe-oxyhydroxide), which is continuously precipitating in aquifers as grain coatings and subsequently transforming to more stable phases. The fate of U adsorbed to ferrihydrite remains a major question. Previous work (e.g., (1-3)) suggests that incorporation of U directly into the Fe-(oxyhydr)oxide structure may be an important process that provides a large sink capacity for subsurface uranium. Little is known about this process and the accompanying mechanisms. We have investigated the structural aspects of freshly precipitated ferrihydrite formed in the presence of varying amounts of U(VI) as UO22+ and in the absence and presence of important ground water solutes, including calcium (Ca2+) and carbonate (CO32-); these ions are also thought to play a role in U(VI) incorporation (3). In addition, we have evaluated the products formed after aging of U-sorbed ferrihydrites at ambient temperature, circum-neutral pH, and with dissolved Fe(II) present to promote redox cycling. Preliminary results indicate that during aging, the reduction of U-sorbed ferrihydrite leads to a change in the coordination of U in the reaction products, most notably the loss of uranyl cation coordination and evidence for possible structural incorporation. Additional powder diffraction, x-ray photoelectron spectroscopy, and high-energy total scattering/PDF data will be presented. This research will lead to an improved understanding of the

  17. Hydrogen incorporation and radiation induced dynamics in metal-oxide-silicon structures. A study using nuclear reaction analysis

    International Nuclear Information System (INIS)

    Resonant nuclear reaction analysis, using the 1H(15N, αγ)12C reaction at 6.4 MeV, has been successfully applied to the investigation of hydrogen incorporation and radiation induced migration in metal-oxide-silicon structures. A preliminary study of the influence of processing parameters on the H content of thermal oxides, with and without gate material present, has been performed. It is found that the dominant source of hydrogen in Al gate devices and dry oxides is often contamination, likely in the form of adsorbed water vapor, formed upon exposure to room air after removal from the oxidation furnace. Concentrations of hydrogen in the bulk oxide as high as 3 1020 cm-3 (Al gate), and as low as 1 1018 cm-3 (poly Si-gate) have been observed. Hydrogen accumulation at the Si-SiO2 interface has been reproducibly demonstrated for as-oxidized samples, as well as for oxides exposed to H2 containing atmospheres during subsequent thermal processing. The migration of hydrogen, from the bulk oxide to the silicon-oxide interface during NRA, has been observed and intensively investigated. A direct correlation between the hydrogen content of the bulk oxide and the radiation generated oxide charges and interface states is presented. These data provide strong support for the important role of hydrogen in determining the radiation sensitivity of electronic devices. (orig.)

  18. Cytotoxic and Oxidative Stress Caused by Cadmium and Lead on Human Skin Fibroblast Cells

    Directory of Open Access Journals (Sweden)

    Ali Beman Zaree Mahmodabady

    2006-01-01

    Full Text Available Introduction: Heavy metals are important occupational andenvironmental pollutants that cause damage to various organs.Although there is no effective therapy for such a poisoning,metallothionein has been shown to play a key role in thedetoxification of cadmium (Cd. Evidence in the literature suggeststhat superoxide dismutase, glutathione peroxidase, and catalaseconstitute important defense mechanisms against oxygen toxicity inthe cells. The aim of this study was to investigate the effect ofcadmium chloride and Pb-acetate on antioxidant enzymes in thehuman skin fibroblast cells (HF2FF.Material and Methods: The human skin fibroblast (HF2FF cellswere incubated in serum-free medium containing 20 μM CdCl2 for18 hr three times a week. The same exposure to an equimolar doseof Pb-acetate was performed. After each exposure and after threetimes exposure the cells were collected and cell viability, thecontents of superoxide dismutase (SOD, catalase, glutathioneperoxidase (GSH-Px, GSH and malondialdehyde (MDA weremeasured.Results: Cd caused cytotoxicity and inhibition of glutathioneperoxidase (GSH-Px and SOD activity, as well as depletion of thereduced form of glutathione (GSH in the cell. The level of lipidperoxidation (LP was increased, but catalase activity was notsignificantly altered. These defects were increased with repeatedexposures. The same exposure to an equimolar dose of Pb-acetateevoked only inhibition of GSH-Px and SOD. The values of GSH,catalase and LP activity remained unchanged.Conclusion: The inhibition of GSH-Px and SOD may be consideredas an important biomarker of the toxic effect of metals.

  19. Photocatalytic Oxidation of Hydrosulfide Ions by Molecular Oxygen Over Cadmium Sulfide Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Raevskaya, A. E., E-mail: photochem@e-mail.ru; Stroyuk, A.L., E-mail: photochem@e-mail.ru; Kuchmii, S.Ya. [National Academy of Sciences of Ukraine, L. V. Pysarzhevsky Institute of Physical Chemistry (Ukraine)], E-mail: photochem@e-mail.ru

    2004-06-15

    Photocatalytic activity of CdS nanoparticles in hydrosulfide-ions air oxidation was revealed and thoroughly investigated. HS{sup -} photooxidation in the presence of CdS nanoparticles results predominantly in the formation of SO{sub 3}{sup 2-} and SO{sub 4}{sup 2-} ions. Photocatalytic activity of ultrasmall CdS crystallites in HS{sup -} photooxidation is much more pronounced as compared to bulk CdS crystals due to high surface area of nanoparticles, their negligible light scattering, improved separation of photogenerated charge carriers etc. It was shown that hydrosulfide ions can be oxidized in two ways. The first is HS{sup -} oxidation by the CdS valence band holes. This process rate depends on the rate of comparatively slow reaction between molecular oxygen and CdS conduction band electrons. The second reaction route is the chain-radical HS{sup -} oxidation induced by photoexcited CdS nanoparticles and propagating in the bulk of a solution. In conditions favourable to chain-radical oxidation of HS{sup -}(i.e. at low light intensities and CdS concentration and high oxygen and Na{sub 2}S concentrations) quantum yields of the photoreaction reach 2.5.

  20. Solanum torvum Swartz. fruit attenuates cadmium-induced liver and kidney damage through modulation of oxidative stress and glycosylation.

    Science.gov (United States)

    Ramamurthy, C H; Subastri, A; Suyavaran, A; Subbaiah, K C V; Valluru, L; Thirunavukkarasu, C

    2016-04-01

    Increased levels of environmental pollutants are linked to almost all human disorders; the efficient method to manage the human health is through naturally available dietary molecule. Solanum torvum (ST) Swartz (Solanaceae) commonly called Turkey Berry is found in Africa, Asia, and South America. Its fruit, part of traditional Indian cuisine, is a widely consumed nutritious herb, acclaimed for its medicinal value. ST aqueous extract (STAe) (250, 500, and 1000 mg/kg b.w., 6 days; oral) against acute Cadmium (Cd) (6.3 mg/kg b.w., single dose; oral) toxicity was evaluated in rats. Protective effect was assessed using serum markers, tissue antioxidants, oxidant derivatives, glycoprotein, and histopathological studies. The activities of serum marker enzymes were increased (40-60 %); antioxidant enzymes such as SOD and CAT, GSH, and its metabolic enzyme activities were decreased (50-80 %) in the liver and kidney upon Cd intoxication. During STAe pre-treatment, at doses of 250 and 500 mg/kg b.w., the above changes were brought to near normal (25-63 %). Tissue 4-hydroxynonenal, 3-nitrotyrosine, and protein carbonyls were increased (8-15 fold) in Cd-alone-treated rats, whereas pre-supplementation of STAe significantly decreased their levels and inhibited the protein glycosylation effectively. The pharmacological effect of STAe was confirmed by histopathological observations. Based on previous literature and present investigation, we conclude that ST may serve as a potential functional food against environmental contaminant such as heavy metal-induced oxidative stress. PMID:26762936

  1. Graphene oxide nanoflakes incorporated gelatin-hydroxyapatite scaffolds enhance osteogenic differentiation of human mesenchymal stem cells

    Science.gov (United States)

    Nair, Manitha; Nancy, D.; Krishnan, Amit G.; Anjusree, G. S.; Vadukumpully, Sajini; Nair, Shantikumar V.

    2015-04-01

    In this study, graphene oxide (GO) nanoflakes (0.5 and 1 wt%) were incorporated into a gelatin-hydroxyapatite (GHA) matrix through a freeze drying technique and its effect to enhance mechanical strength and osteogenic differentiation was studied. The GHA matrix with GO demonstrated less brittleness in comparison to GHA scaffolds. There was no significant difference in mechanical strength between GOGHA0.5 and GOGHA1.0 scaffolds. When the scaffolds were immersed in phosphate buffered saline (to mimic physiologic condition) for 60 days, around 50-60% of GO was released in sustained and linear manner and the concentration was within the toxicity limit as reported earlier. Further, GOGHA0.5 scaffolds were continued for cell culture experiments, wherein the scaffold induced osteogenic differentiation of human adipose derived mesenchymal stem cells without providing supplements like dexamethasone, L-ascorbic acid and β glycerophosphate in the medium. The level of osteogenic differentiation of stem cells was comparable to those cultured on GHA scaffolds with osteogenic supplements. Thus biocompatible, biodegradable and porous GO reinforced gelatin-HA 3D scaffolds may serve as a suitable candidate in promoting bone regeneration in orthopaedics.

  2. Antibacterial TiO2Coating Incorporating Silver Nanoparticles by Micro arc Oxidation and Ion Implantation

    International Nuclear Information System (INIS)

    Infection associated with titanium implants remains the most common serious complication in hard tissue replacement surgery. Since such postoperative infections are usually difficult to cure, it is critical to find optimal strategies for preventing infections. In this study, TiO2 coating incorporating silver (Ag) nanoparticles were fabricated on pure titanium by micro arc oxidation and ion implantation. The antibacterial activity was evaluated by exposing the specimens to Staphylococcus aureus and comparing the reaction of the pathogens to Ti-MAO-Ag with Ti-MAO controls. Ti-MAO-Ag clearly inhibited bacterial colonization more than the control specimen. The coating’s antibacterial ability was enhanced by increasing the dose of silver ion implantation, and Ti-MAO-Ag 20.0 had the best antibacterial ability. In addition, cytocompatibility was assessed by culturing cell colonies on the specimens. The cells grew well on both specimens. These findings indicate that surface modification by means of this process combining MAO and silver ion implantation is useful in providing antibacterial activity and exhibits cytocompatibility with titanium implants

  3. The incorporation of graphene oxide into polysulfone mixed matrix membrane for CO2/CH4 separation

    Science.gov (United States)

    Zahri, K.; Goh, P. S.; Ismail, A. F.

    2016-06-01

    Carbon dioxide (CO2) is often found as the main impurity in natural gas, where methane (CH4) is the major component. The presence of CO2 in natural gas leads to several problems such as reducing the energy content of natural gas and cause pipeline corrosion. Thus it must be removed to meet specifications (CO2 ≤ 2 mol%) before the gas can be delivered to the pipeline. In this work, hollow fiber mixed matrix membrane (MMM) were fabricated by embedding graphene oxide (GO) into a polysulfone (PSf) polymer matrix to improve membrane properties as well as its separation performance towards CO2/CH4 gas. The membrane properties were investigated for pristine membrane and mixed matrix membrane filled with filler loading of 0.25%. The synthesized GO and properties of fabricated membranes were characterized and studied using TEM, AFM, XRD, FTIR and SEM respectively. The permeance of pure gases and ideal selectivity of CO2/CH4 gas were determined using pure gas permeation experiment. GO has affinity towards CO2 gas. The nanosheet structure creates path for small molecule gas and restricted large molecule gas to pass through the membrane. The incorporation of GO in PSf polymer enhanced the permeance of CO 2 and CO2/CH4 separation from 64.47 to 86.80 GPU and from 19 to 25 respectively.

  4. Exciting imperfection. Real-structure effects in magnesium-, cadmium-, and zinc-oxide

    Energy Technology Data Exchange (ETDEWEB)

    Schleife, Andre

    2010-07-01

    We employ recent ab-initio methods and theoretical spectroscopy techniques that rely on heavy numerical calculations to describe electronic excitations in non-ideal crystals of three group-II oxides. We study the ideal equilibrium polymorphs of these oxides, for gaining a thorough understanding as well as the necessary confidence in our approaches to generalize and apply them to the electronic excitations in imperfect crystals. As such imperfections we take the influence of strain, the alloying of the different oxides, an intrinsic point defect, and free electrons in the lowest conduction band into account. We employ the DFT results as input in order to compute quasiparticle electronic structures, which are in good agreement with experimental findings. According to Hedin's equations for interacting electrons, the electron-hole interaction is taken into account by solving a Bethe-Salpeter equation for the polarization function. Thereafter the equilibrium polymorphs of ideal bulk MgO, ZnO, and CdO and investigates the structure of their valence and conduction bands are described. We present densities of states and effective masses, as well as natural band discontinuities. Furthermore, our description of the dielectric function, which takes excitonic effects into account, enables us to derive the electron-energy loss function. The influence of uniaxial and biaxial strain on the ordering of the valence bands in ZnO is investigated. In addition, we explore the electronic band structure of the non-equilibrium wurtzite structures of MgO and CdO. We predict valence-band splittings and band gaps as they might occur at interfaces of Mgo or CdO with ZnO substrates. Thereafter we study pseudobinary alloys by means of a cluster expansion method. Due to the different crystal structures of the respective oxides, i.e. rocksalt and wurtzite, the description of their heterostructural combination has to be achieved. The electronic and optical properties of the group-II oxide

  5. Exciting imperfection. Real-structure effects in magnesium-, cadmium-, and zinc-oxide

    International Nuclear Information System (INIS)

    We employ recent ab-initio methods and theoretical spectroscopy techniques that rely on heavy numerical calculations to describe electronic excitations in non-ideal crystals of three group-II oxides. We study the ideal equilibrium polymorphs of these oxides, for gaining a thorough understanding as well as the necessary confidence in our approaches to generalize and apply them to the electronic excitations in imperfect crystals. As such imperfections we take the influence of strain, the alloying of the different oxides, an intrinsic point defect, and free electrons in the lowest conduction band into account. We employ the DFT results as input in order to compute quasiparticle electronic structures, which are in good agreement with experimental findings. According to Hedin's equations for interacting electrons, the electron-hole interaction is taken into account by solving a Bethe-Salpeter equation for the polarization function. Thereafter the equilibrium polymorphs of ideal bulk MgO, ZnO, and CdO and investigates the structure of their valence and conduction bands are described. We present densities of states and effective masses, as well as natural band discontinuities. Furthermore, our description of the dielectric function, which takes excitonic effects into account, enables us to derive the electron-energy loss function. The influence of uniaxial and biaxial strain on the ordering of the valence bands in ZnO is investigated. In addition, we explore the electronic band structure of the non-equilibrium wurtzite structures of MgO and CdO. We predict valence-band splittings and band gaps as they might occur at interfaces of Mgo or CdO with ZnO substrates. Thereafter we study pseudobinary alloys by means of a cluster expansion method. Due to the different crystal structures of the respective oxides, i.e. rocksalt and wurtzite, the description of their heterostructural combination has to be achieved. The electronic and optical properties of the group-II oxide alloys

  6. Comparison of cadmium-induced oxidative stress in Brassica juncea in soil and hydroponic cultures

    OpenAIRE

    Armas, Teresa; Pinto, Ana Paula; de Varennes, Amarilis; Mourato, Manuel Pedro; Martins, Luisa Louro; Gonçalves, Maria de Lurdes Simões; Mota, Ana Maria

    2014-01-01

    Abstract Aims The objective of this study was to investigate the response of Brassica juncea in the presence of Cd, in hydroponic and soil experiments, and to conclude about common and divergent trends in both cultures. Methods We studied the effect of Cd on growth, oxidative damage and antioxidant responses in roots and shoots of B. juncea grown in soil and hydroponic cultures, using typical time-scales for each one. Major ROS-scavenging enzymes such as catalase, ascorbate peroxidase a...

  7. Characterization of natural organic matter treated by iron oxide nanoparticle incorporated ceramic membrane-ozonation process.

    Science.gov (United States)

    Park, Hosik; Kim, Yohan; An, Byungryul; Choi, Heechul

    2012-11-15

    In this study, changes in the physical and structural properties of natural organic matter (NOM) were observed during hybrid ceramic membrane processes that combined ozonation with ultrafiltration ceramic membrane (CM) or with a reactive ceramic membrane (RM), namely, an iron oxide nanoparticles (IONs) incorporated-CM. NOM from feed water and NOM from permeate treated with hybrid ceramic membrane processes were analyzed by employing several NOM characterization techniques. Specific ultraviolet absorbance (SUVA), high-performance size exclusion chromatography (HPSEC) and fractionation analyses showed that the hybrid ceramic membrane process effectively removed and transformed relatively high contents of aromatic, high molecular weight and hydrophobic NOM fractions. Fourier transform infrared spectroscopy (FTIR) and 3-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy revealed that this process caused a significant decrease of the aromaticity of humic-like structures and an increase in electron withdrawing groups. The highest removal efficiency (46%) of hydroxyl radical probe compound (i.e., para-Chlorobenzoic acid (pCBA)) in RM-ozonation process compared with that in CM without ozonation process (8%) revealed the hydroxyl radical formation by the surface-catalyzed reaction between ozone and IONs on the surface of RM. In addition, experimental results on flux decline showed that fouling of RM-ozonation process (15%) was reduced compared with that of CM without ozonation process (30%). These results indicated that the RM-ozonation process enhanced the destruction of NOM and reduced the fouling by generating hydroxyl radicals from the catalytic ozonation in the RM-ozonation process. PMID:22944203

  8. Preparation, Characterization and Tests of Incorporation in Stem Cells of Superparamagnetic Iron Oxide

    Science.gov (United States)

    Haddad, P. S.; Britos, T. N.; Li, L. M.; Li, L. D. S.

    2015-05-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) have been produced and used as contrast-enhancing agents in magnetic resonance imaging (MRI) for diagnostic use in a wide range of maladies including cardiovascular, neurological disorders, and cancer. The reasons why these SPIONs are attractive for medical purposes are based on their important and unique features. The large surface area of the nanoparticles and their manipulation through an external magnetic field are features that allow their use for carrying a large number of molecules such as biomolecules or drugs. In this scenario, the present work reports on the synthesis and characterization of SPIONs and in vitro MRI experiments to increase their capacity as probes for MRI applications on stem cells therapy. Initially, the SPIONs were prepared through the co-precipitation method using ferrous and ferric chlorides in acidic solution. The SPIONs were coated with two thiolmolecules such as mercaptosuccinic acid (MSA) and cysteine (Cys) (molar ratio SPIONs:ligand = 1:20), leading to the formation of a stable aqueous dispersion of thiolated nanoparticles (SH-SPIONs). The SH-SPIONs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results showed that the SH-SPIONs have a mean diameter of 14 nm and display superparamagnetic behavior at room temperature. Preliminary tests of incorporation of SH-SPIONs were evaluated stem cells. The results showed that the thiolated nanoparticles have no toxic effects for stem cells and successfully internalized and enhance the contrast in MRI.

  9. Oxidation and sensing of ascorbic acid and dopamine on self-assembled gold nanoparticles incorporated within polyaniline film

    Science.gov (United States)

    Chu, Wenya; Zhou, Qun; Li, Shuangshuang; Zhao, Wei; Li, Na; Zheng, Junwei

    2015-10-01

    Electrochemical biosensors based on conducting polymers incorporated with metallic nanoparticles can greatly enhance sensitivity and selectivity. Herein, we report a facile fabrication approach for polyaniline (PAN) incorporated with a gold nanoparticle (AuNP) composite electrode by electrodeposition of PAN on a self-assembled AuNP layer on the surface of an indium tin oxide electrode. The resulting AuNP/PAN composite electrode exhibits a remarkable synergistic effect on the electrocatalytic oxidation of ascorbic acid (AA) and dopamine (DA). It is demonstrated that the oxidation reaction of AA mainly occurs at AuNPs inside the PAN film as the ascorbate anions are doped into the polymer during the oxidation of the PAN film. Conversely, the oxidation of positively charged DA may only take place at the PAN/solution interface. The different mechanisms of the electrode reactions result in the oxidation of AA and DA occurring at different potentials. As a result, the AuNP/PAN composite electrode can be employed to simultaneously detect AA and DA with a good linear range, high sensitivity, and low detection limit.

  10. Gibberellic acid alleviates cadmium toxicity by reducing nitric oxide accumulation and expression of IRT1 in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiao Fang [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Jiang, Tao [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Wang, Zhi Wei [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Lei, Gui Jie [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Shi, Yuan Zhi [The Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Yunqi Road 1, Hangzhou 310008 (China); Li, Gui Xin, E-mail: guixinli@zju.edu.cn [College of Agronomy and Biotechnology, Zhejiang University, Hangzhou 310058 (China); Zheng, Shao Jian [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Cd reduces endogenous GA levels in Arabidopsis. Black-Right-Pointing-Pointer GA exogenous applied decreases Cd accumulation in plant. Black-Right-Pointing-Pointer GA suppresses the Cd-induced accumulation of NO. Black-Right-Pointing-Pointer Decreased NO level downregulates the expression of IRT1. Black-Right-Pointing-Pointer Suppressed IRT1 expression reduces Cd transport across plasma membrane. - Abstract: Gibberellic acid (GA) is involved in not only plant growth and development but also plant responses to abiotic stresses. Here it was found that treating the plants with GA concentrations from 0.1 to 5 {mu}M for 24 h had no obvious effect on root elongation in the absence of cadmium (Cd), whereas in the presence of Cd{sup 2+}, GA at 5 {mu}M improved root growth, reduced Cd content and lipid peroxidation in the roots, indicating that GA can partially alleviate Cd toxicity. Cd{sup 2+} increased nitric oxide (NO) accumulation in the roots, but GA remarkably reduced it, and suppressed the up-regulation of the expression of IRT1. In contrary, the beneficial effect of GA on alleviating Cd toxicity was not observed in an IRT1 knock-out mutant irt1, suggesting the involvement of IRT1 in Cd{sup 2+} absorption. Furthermore, the GA-induced reduction of NO and Cd content can also be partially reversed by the application of a NO donor (S-nitrosoglutathione [GSNO]). Taken all these together, the results showed that GA-alleviated Cd toxicity is mediated through the reduction of the Cd-dependent NO accumulation and expression of Cd{sup 2+} uptake related gene-IRT1 in Arabidopsis.

  11. Effect of Sodium Chloride and Cadmium on the Growth, Oxidative Stress and Antioxidant Enzyme Activities of Zygosaccharomyces rouxii

    Institute of Scientific and Technical Information of China (English)

    LI Chunsheng; XU Ying; JIANG Wei; LV Xin; DONG Xiaoyan

    2014-01-01

    Zygosaccharomyces rouxii is a salt-tolerant yeast species capable of removing cadmium (Cd) pollutant from aqueous solution. Presently, the physiological characteristics of Z. rouxii under the stress of sodium chloride (NaCl) and Cd are poorly under-stood. This study investigated the effects of NaCl and Cd on the growth, oxidative stress and antioxidant enzyme activities of Z. rouxii after stress treatment for 24 h. Results showed that NaCl or Cd alone negatively affected the growth of Z. rouxii, but the growth-inhibiting effect of Cd on Z. rouxii was reduced in the presence of NaCl. Flow cytometry assay showed that under Cd stress, NaCl significantly reduced the production of reactive oxygen species (ROS) and cell death of Z. rouxii compared with those in the absence of NaCl. The activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) of Z. rouxii were significantly enhanced by 2%-6%NaCl, which likely contributed to the high salt tolerance of Z. rouxii. The POD activity was inhibited by 20 mg L-1 Cd while the SOD and CAT activities were enhanced by 8 mg L-1 Cd and inhibited by 20 mg L-1 or 50 mg L-1 Cd. The inhibitory ef-fect of high-level Cd on the antioxidant enzyme activities of Z. rouxii was counteracted by the combined use of NaCl, especially at 6%. This probably accounted for the decrease in Cd-induced ROS production and cell death of Z. rouxii after incubation with NaCl and Cd. Our work provided physiological clues as to the use of Z. rouxii as a biosorbent for Cd removal from seawater and liquid highly salty food.

  12. Effect of sodium chloride and cadmium on the growth, oxidative stress and antioxidant enzyme activities of Zygosaccharomyces rouxii

    Science.gov (United States)

    Li, Chunsheng; Xu, Ying; Jiang, Wei; Lv, Xin; Dong, Xiaoyan

    2014-06-01

    Zygosaccharomyces rouxii is a salt-tolerant yeast species capable of removing cadmium (Cd) pollutant from aqueous solution. Presently, the physiological characteristics of Z. rouxii under the stress of sodium chloride (NaCl) and Cd are poorly understood. This study investigated the effects of NaCl and Cd on the growth, oxidative stress and antioxidant enzyme activities of Z. rouxii after stress treatment for 24 h. Results showed that NaCl or Cd alone negatively affected the growth of Z. rouxii, but the growth-inhibiting effect of Cd on Z. rouxii was reduced in the presence of NaCl. Flow cytometry assay showed that under Cd stress, NaCl significantly reduced the production of reactive oxygen species (ROS) and cell death of Z. rouxii compared with those in the absence of NaCl. The activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) of Z. rouxii were significantly enhanced by 2%-6% NaCl, which likely contributed to the high salt tolerance of Z. rouxii. The POD activity was inhibited by 20 mg L-1 Cd while the SOD and CAT activities were enhanced by 8 mg L-1 Cd and inhibited by 20 mg L-1 or 50 mg L-1 Cd. The inhibitory effect of high-level Cd on the antioxidant enzyme activities of Z. rouxii was counteracted by the combined use of NaCl, especially at 6%. This probably accounted for the decrease in Cd-induced ROS production and cell death of Z. rouxii after incubation with NaCl and Cd. Our work provided physiological clues as to the use of Z. rouxii as a biosorbent for Cd removal from seawater and liquid highly salty food.

  13. Lanthanum rather than cadmium induces oxidative stress and metabolite changes in Hypericum perforatum

    Energy Technology Data Exchange (ETDEWEB)

    Babula, Petr [Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 753/5, 625 00 Brno (Czech Republic); Klejdus, Bořivoj [Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno (Czech Republic); CEITEC–Central European Institute of Technology, Mendel University in Brno, Zemědělská 1, 613 00 Brno (Czech Republic); Kovacik, Jozef, E-mail: jozkovacik@yahoo.com [Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno (Czech Republic); CEITEC–Central European Institute of Technology, Mendel University in Brno, Zemědělská 1, 613 00 Brno (Czech Republic); Hedbavny, Josef; Hlavna, Marián [Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno (Czech Republic)

    2015-04-09

    Highlights: • Impact of La, Cd and Cd + La on the metabolism of Hypericum perforatum was compared. • La stimulated ROS and suppressed growth and basic antioxidants more than Cd. • Impact of Cd + La was not synergistic including the sod gene expression. • La depleted hypericin and hyp-1 gene expression but amount of hyperforin increased. • La reduced flavonols and procyanidins mainly in the roots and affected anatomy - Abstract: Physiology, oxidative stress and production of metabolites in Hypericum perforatum exposed to moderate Cd and/or La concentration (10 μM) were studied. La evoked increase in reactive oxygen species, malondialdehyde and proline but suppressed growth, tissue water content, glutathione, ascorbic acid and affected mineral nutrient contents more than Cd while the impact of Cd + La was not synergistic. Similar trend was observed at the level of superoxide dismutase gene expression. Shoot Cd amount increased in Cd + La while only root La increased in the same treatment. Extensive quantification of secondary metabolites revealed that La affected phenolic acids more pronouncedly than Cd in shoots and roots. Flavonols were suppressed by La that could contribute to the appearance of oxidative damage. Procyanidins increased in response to La in the shoots but decreased in the roots. Metabolic responses in Cd + La treatment resembled those of La treatment (almost identically in the roots). Phenylalanine ammonia-lyase activity was mainly suppressed by La. The presence of La also depleted amount of hypericin and expression of its putative gene (hyp-1) showed similar trend but accumulation of hyperforin increased under Cd or La excess. Clear differences in the stem and root anatomy in response to Cd or La were also found. Overall, H. perforatum is La-sensitive species and rather Cd ameliorated negative impact of La.

  14. Amelioration Effect of Zinc and Iron Supplementation on Selected Oxidative Stress Enzymes in Liver and Kidney of Cadmium-Treated Male Albino Rat.

    Science.gov (United States)

    Jamakala, Obaiah; Rani, Usha A

    2015-01-01

    Cadmium (Cd) is a highly toxic, nonessential heavy metal with many industrial uses that can contribute to a well-defined spectrum of diseases in animals as well as in humans. The present study examines the effect of zinc (Zn) and iron (Fe) supplementation on oxidative stress enzymes in Cd-treated rats. Wistar strain male albino rats were treated with cadmium chloride (CdCl2) at a dose of 1/10(th) LD50/48 h, that is, 22.5 mg/kg body weight for 7, 15, and 30 days (d) time intervals. The 15d Cd-treated rats were divided into three groups. The first group received Zn (12 mg/kg), second group Fe (40 mg/kg) alone, and third group supplemented with both Zn and Fe and observed for 7, 15, and 30d. After the specific time intervals, rats were decapitated and oxidative stress enzymes like catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed in liver and kidney. Simultaneously lipid peroxidation (LPO) levels were also measured. A significant elevation in LPO levels with decreased activity levels of CAT, SOD, GPx, and GST were observed during Cd intoxication. With Zn and/or Fe supplementation, a significant reversal in the oxidative stress enzymes was observed. Our study reveals that combination of Zn and Fe supplementation is effective in detoxifying the Cd body burden from the test tissues. PMID:26862254

  15. Comparative Assessment of Antimicrobial Efficiency of Ionic Silver, Silver Monoxide, and Metallic Silver Incorporated onto an Aluminum Oxide Nanopowder Carrier

    OpenAIRE

    Agnieszka Maria Jastrzębska; Ewa Karwowska; Andrzej R. Olszyna; Antoni R. Kunicki

    2013-01-01

    The present paper provides comparative assessment of antimicrobial efficiency of ionic silver (Ag+), silver monoxide (Ag2O), and metallic silver (Ag) incorporated onto an aluminum oxide nanopowder carrier (Al2O3). The deposition of Ag+ ions, Ag2O nanoparticles, and Ag nanoparticles on an different phases of aluminum oxide nanopowder carrier was realized using consecutive stages of dry sol-gel method. The Al2O3-Ag+, Al2O3-Ag2O, and Al2O3-Ag nanopowders were widely characterized qualitatively a...

  16. Preparation of cadmium-doped ZnO thin films by SILAR and their characterization

    Indian Academy of Sciences (India)

    S Mondal; P Mitra

    2012-10-01

    Cadmium-doped zinc oxide (Cd : ZnO) thin films were deposited from sodium zincate bath following a chemical dipping technique called successive ion layer adsorption and reaction (SILAR). Structural characterization by X-ray diffraction reveals that polycrystalline nature of the films increases with increasing cadmium incorporation. Particle size evaluated using X-ray line broadening analysis shows decreasing trend with increasing cadmium impurification. The average particle size for pure ZnO is 36.73nm and it reduces to 29.9 nm for 10% Cd:ZnO, neglecting strain broadening. The strong preferred c-axis orientation is lost due to cadmium doping and degree of polycrystallinity of the films also increases with increasing Cd incorporation. Incorporation of cadmium was confirmed from elemental analysis using EDX. The optical bandgap of the films decreases with increasing Cd dopant. The value of fundamental absorption edge is 3.18 eV for pure ZnO and it decreases to 3.11 eV for 10% Cd:ZnO.

  17. Micro-structural characterization of annealed cadmium-zinc oxide thin films obtained by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Gandarilla, F.; Morales-Acevedo, Arturo; Vigil, O.; Hesiquio-Garduno, M.; Vaillant, L.; Contreras-Puente, G

    2003-02-28

    The structural properties of annealed (ZnO){sub x}(CdO){sub 1-x} thin films are studied by x-ray diffraction methods. The films were obtained by spray pyrolysis using different values for the nominal composition (x), and then they were annealed at 450 deg. C from 0 to 120 min. The structural analysis confirms previous results on the formation of a homogeneously mixed oxide semiconductor, but in which crystalline and amorphous phases co-exist for both CdO and ZnO. In this work, we show that for annealed films there is a strong interaction between the amorphous, the hexagonal ZnO and the cubic CdO phases regarding the lattice constants and the crystallite growth rate. In the annealed films, for x{<=}0.5 the optical behavior is mainly controlled by the CdO phase, so that there is a reduction of the effective band-gap of the material when the CdO crystallite size is increased, possibly due to grain size effects. On the other hand, for x>0.5 the band-gap behavior is mainly determined by the variation of the ZnO crystallite lattice parameters and the relative volumetric concentration of amorphous and crystalline ZnO in the film.

  18. Effect of aniline on cadmium adsorption by sulfanilic acid-grafted magnetic graphene oxide sheets.

    Science.gov (United States)

    Hu, Xin-jiang; Liu, Yun-guo; Zeng, Guang-ming; Wang, Hui; Hu, Xi; Chen, An-wei; Wang, Ya-qin; Guo, Yi-Mming; Li, Ting-ting; Zhou, Lu; Liu, Shao-heng; Zeng, Xiao-xia

    2014-07-15

    Cd(II) has posed severe health risks worldwide. To remove this contaminant from aqueous solution, the sulfanilic acid-grafted magnetic graphene oxide sheets (MGOs/SA) were prepared and characterized. The mutual effects of Cd(II) and aniline adsorption on MGOs/SA were studied. The effects of operating parameters such as pH, ionic strength, contact time and temperature on the Cd(II) enrichment, as well as the adsorption kinetics and isotherm were also investigated. The results demonstrated that MGOs/SA could effectively remove Cd(II) and aniline from the aqueous solution and the two adsorption processes were strongly dependent on solution pH. The Cd(II) adsorption was reduced by the presence of aniline at pH5.4. The presence of Cd(II) diminished the adsorption capacity for aniline at pH7.8. The decontamination of Cd(II) by MGOs/SA was influenced by ionic strength. Besides, the adsorption process could be well described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that the intraparticle diffusion was not the only rate-limiting step for the adsorption process. Moreover, the experimental data of isotherm followed the Freundlich isotherm model.

  19. Unexpected behavior of some nitric oxide modulators under cadmium excess in plant tissue.

    Directory of Open Access Journals (Sweden)

    Jozef Kováčik

    Full Text Available Various nitric oxide modulators (NO donors--SNP, GSNO, DEA NONOate and scavengers--PTIO, cPTIO were tested to highlight the role of NO under Cd excess in various ontogenetic stages of chamomile (Matricaria chamomilla. Surprisingly, compared to Cd alone, SNP and PTIO elevated Cd uptake (confirmed also by PhenGreen staining but depleted glutathione (partially ascorbic acid and phytochelatins PC2 and PC3 in both older plants (cultured hydroponically and seedlings (cultured in deionised water. Despite these anomalous impacts, fluorescence staining of NO and ROS confirmed predictable assumptions and revealed reciprocal changes (decrease in NO but increase in ROS after PTIO addition and the opposite after SNP application. Subsequent tests using alternative modulators and seedlings confirmed changes to NO and ROS after application of GSNO and DEA NONOate as mentioned above for SNP while cPTIO altered only NO level (depletion. On the contrary to SNP and PTIO, GSNO, DEA NONOate and cPTIO did not elevate Cd content and phytochelatins (PC2, PC3 were rather elevated. These data provide evidence that various NO modulators are useful in terms of NO and ROS manipulation but interactions with intact plants affect metal uptake and must therefore be used with caution. In this view, cPTIO and DEA NONOate revealed the less pronounced side impacts and are recommended as suitable NO scavenger/donor in plant physiological studies under Cd excess.

  20. Effect of aniline on cadmium adsorption by sulfanilic acid-grafted magnetic graphene oxide sheets.

    Science.gov (United States)

    Hu, Xin-jiang; Liu, Yun-guo; Zeng, Guang-ming; Wang, Hui; Hu, Xi; Chen, An-wei; Wang, Ya-qin; Guo, Yi-Mming; Li, Ting-ting; Zhou, Lu; Liu, Shao-heng; Zeng, Xiao-xia

    2014-07-15

    Cd(II) has posed severe health risks worldwide. To remove this contaminant from aqueous solution, the sulfanilic acid-grafted magnetic graphene oxide sheets (MGOs/SA) were prepared and characterized. The mutual effects of Cd(II) and aniline adsorption on MGOs/SA were studied. The effects of operating parameters such as pH, ionic strength, contact time and temperature on the Cd(II) enrichment, as well as the adsorption kinetics and isotherm were also investigated. The results demonstrated that MGOs/SA could effectively remove Cd(II) and aniline from the aqueous solution and the two adsorption processes were strongly dependent on solution pH. The Cd(II) adsorption was reduced by the presence of aniline at pH5.4. The presence of Cd(II) diminished the adsorption capacity for aniline at pHadsorption at pH>7.8. The decontamination of Cd(II) by MGOs/SA was influenced by ionic strength. Besides, the adsorption process could be well described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that the intraparticle diffusion was not the only rate-limiting step for the adsorption process. Moreover, the experimental data of isotherm followed the Freundlich isotherm model. PMID:24863786

  1. Alkaline deoxygenated graphene oxide as adsorbent for cadmium ions removal from aqueous solutions.

    Science.gov (United States)

    Liu, Jun; Du, Hongyan; Yuan, Shaowei; He, Wanxia; Yan, Pengju; Liu, Zhanhong

    2015-01-01

    Alkaline deoxygenated graphene oxide (aGO) was prepared through alkaline hydrothermal treatment and used as adsorbent to remove Cd(II) ions from aqueous solutions for the first time. The characterization results of transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared (FT-IR) spectra indicate that aGO was successfully synthesized. The batch adsorption experiments showed that the adsorption kinetics could be described by the pseudo-second-order kinetic model, and the isotherms equilibrium data were well fitted with the Langmuir model. The maximum adsorption capacity of Cd(II) on aGO was 156 mg/g at pH 5 and T=293 K. The adsorption thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic reaction. The mainly adsorption mechanism speculated from FT-IR results may be attributed to the electrostatic attraction between Cd2+ and negatively charged groups (-CO-) of aGO and cation-π interaction between Cd2+ and the graphene planes. The findings of this study demonstrate the potential utility of the nanomaterial aGO as an effective adsorbent for Cd(II) removal from aqueous solutions. PMID:26038925

  2. Cadmium-induced oxidative stress, response of antioxidants and detection of intracellular cadmium in organs of moso bamboo (Phyllostachys pubescens) seedlings.

    Science.gov (United States)

    Li, Song; Chen, Junren; Islam, Ejazul; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Yan, Wenbo; Peng, Danli; Liu, Dan

    2016-06-01

    Moso bamboo (Phyllostachys pubescens (Pradelle) Mazel ex J.Houz.) is recognized as a potential phytoremediation plant due to its huge biomass and high tolerance to environmental stresses. The objectives of this study were to investigate mechanism related to cadmium (Cd) tolerance and to evaluate Cd accumulation capacity of moso bamboo. The results of the pot experiment showed that Cd accumulation by bamboo increased with increasing the Cd levels in soil and the values in stem ranged from 28.51 to 132.13 mg kg(-1). Meanwhile chlorophyll in leaves and total biomass showed a decreasing trend. The bioaccumulation factors (BAF) for roots and stem in all the treatments were more than 1.0 and the translocation factor (TF) ranged from 0.70 to 1.06. In hydroponics experiment, the concentrations of malondialdehyde (MDA) in the leaves were significantly increased in Cd treated plants as compared with control. The activities of superoxide dismutase (SOD) and peroxidase (POD) were enhanced at initial stage and then decreased consistently with the increase of Cd addition. The proline concentrations were also increased due to the presence of Cd, particularly at 25 μM Cd treatment. According to TEM-EDX analysis, the cytoplasm was the main site for accumulation of Cd in moso bamboo. On the basis of overall results, it is suggested that moso bamboo could be successfully used for the remediation of low Cd (no more than 5 mg kg(-1)) contaminated soils. PMID:27015570

  3. Structural and electrical properties of poly(ethylene oxide)-cadmium sulphate complexes

    Energy Technology Data Exchange (ETDEWEB)

    Zain, N.M.; Arof, A.K. [Malaya Univ., Kuala Lumpur (Malaysia). Dept. of Physics

    1998-03-06

    Solid complexes of poly(ethylene oxide), PEO and 3CdSO{sub 4}.8H{sub 2}O varying from 0 to 25 wt% corresponding to solubility limit Cd{sup 2+}/EO = 0 to 0.019 were prepared by the solution cast technique. X-ray diffraction (XRD) technique shows the presence of a new crystalline phase at Cd{sup 2+}/EO>0.009. Two new peaks are observed at 2{theta}{approx}16 and 27 which is not attributable to PEO or 3CdSO{sub 4}.8H{sub 2}O. These peaks increase in intensity and are accompanied by other peaks as indicated in the diffractograms for samples with higher doping concentration. At low salt concentrations Cd{sup 2+}/EO < 0.009, X-ray diffraction infers the disruption of the crystalline order of the PEO and their conversion to the amorphous state. The cations Cd{sup 2+} and anions [SO{sub 4}]{sup 2-} are therefore dispersed in the amorphous phase of the PEO. The increase in salt concentration in the low salt regime (Cd{sup 2+}/EO < 0.009) increases the amorphous nature of the PEO. This is verified by the variation of the coherent or Scherrer length with Cd{sup 2+}/EO ratio and implies that the highest conducting film is the least crystalline in nature. Absorption spectroscopy shows the occurrence of polymer-salt complexation which involves an interaction between the cation of the salt and the lone pair electrons of the ether oxygen atom. This can be inferred from the peaks present at 1395 and 1912 nm, respectively. Infrared spectra show some shifts in the spectral bands which could be attributed to complexation. 31 refs.

  4. The importance of the methanol content in the precursor solution, on the physical properties of cadmium oxide thin films prepared by the sol-gel method

    International Nuclear Information System (INIS)

    Research highlights: → This work is important due to the recent interest for obtaining CdO films by simple and economical techniques. The sol-gel technique shows these characteristics. However, CdO films with higher thicknesses could be obtained starting from a high number of coats. In this work, the importance of the methanol content in the precursor solution on the physical properties of cadmium oxide thin films prepared by the sol-gel method was studied. For the first time, higher thicknesses of CdO films were obtained with a lower number of coats, changing the methanol content in the precursor solution. The films show good electrical, optical, structural properties for their use as transparent conductive films in solar cells. - Abstract: Undoped and fluorine doped cadmium oxide films were obtained by the sol-gel technique, starting from a simple precursor solution constituted of: cadmium acetate, methanol, glycerol and triethylamine and only for doped samples, ammonium fluoride as the fluoride source. Due to the methanol content used is higher with respect to the other reagents, variations in this parameter affect the viscosity and gelation time of the precursor solution, giving as result changes in the thickness. The importance of the methanol content in the growing solution on the structural, morphological, optical and electrical properties of the films is reported. Higher thickness was obtained for lower methanol content, in the range 33-46 mol, in the growing solution. Largest growing rate was obtained when the methanol content in the precursor solution was 33 mol. The films showed good characteristics for their use as transparent conductive films in solar cells.

  5. Incorporation of Iron Oxide Nanoparticles and Quantum Dots into Silica Microspheres

    OpenAIRE

    Insin, Numpon; Tracy, Joseph B.; Lee, Hakho; Zimmer, John P.; Westervelt, Robert M.; Bawendi, Moungi G.

    2008-01-01

    We describe the synthesis of magnetic and fluorescent silica microspheres fabricated by incorporating maghemite (γ-Fe2O3) nanoparticles (MPs) and CdSe/CdZnS core/shell quantum dots (QDs) into a silica shell around preformed silica microspheres. The resultant 500 nm microspheres have a narrow size distribution and show uniform incorporation of QDs and MPs into the shell. We have demonstrated manipulation of these microspheres using an external magnetic field with real-time fluorescence microsc...

  6. Preparation and Photocatalytic Activity of Potassium- Incorporated Titanium Oxide Nanostructures Produced by the Wet Corrosion Process Using Various Titanium Alloys

    Directory of Open Access Journals (Sweden)

    So Yoon Lee

    2015-08-01

    Full Text Available Nanostructured potassium-incorporated Ti-based oxides have attracted much attention because the incorporated potassium can influence their structural and physico-chemical properties. With the aim of tuning the structural and physical properties, we have demonstrated the wet corrosion process (WCP as a simple method for nanostructure fabrication using various Ti-based materials, namely Ti–6Al–4V alloy (TAV, Ti–Ni (TN alloy and pure Ti, which have 90%, 50% and 100% initial Ti content, respectively. We have systematically investigated the relationship between the Ti content in the initial metal and the precise condition of WCP to control the structural and physical properties of the resulting nanostructures. The WCP treatment involved various concentrations of KOH solutions. The precise conditions for producing K-incorporated nanostructured titanium oxide films (nTOFs were strongly dependent on the Ti content of the initial metal. Ti and TAV yielded one-dimensional nanowires of K-incorporated nTOFs after treatment with 10 mol/L-KOH solution, whereas TN required a higher concentration (20 mol/L-KOH solution to produce comparable nanostructures. The obtained nanostructures revealed a blue-shift in UV absorption spectra due to the quantum confinement effects. A significant enhancement of the photocatalytic activity was observed via the chromomeric change and the intermediate formation of methylene blue molecules under UV irradiation. This study demonstrates the WCP as a simple, versatile and scalable method for the production of nanostructured K-incorporated nTOFs to be used as high-performance photocatalysts for environmental and energy applications.

  7. Facile covalent immobilization of cadmium sulfide quantum dots on graphene oxide nanosheets : preparation, characterization, and optical properties

    NARCIS (Netherlands)

    Pham, Tuan Anh; Choi, Byung Choon; Jeong, Yeon Tae

    2010-01-01

    A facile approach for the preparation of a novel hybrid material containing graphene and an inorganic semiconducting material, cadmium sulfide quantum dots (CdS QDs), is demonstrated for the first time. First, amino-functionalized CdS QDs were prepared by modifications of the kinetic trapping method

  8. Antibacterial properties of composite resins incorporating silver and zinc oxide nanoparticles on Streptococcus mutans and Lactobacillus

    OpenAIRE

    Kasraei, Shahin; Sami, Lida; Hendi, Sareh; AliKhani, Mohammad-Yousef; Rezaei-Soufi, Loghman; Khamverdi, Zahra

    2014-01-01

    Objectives Recurrent caries was partly ascribed to lack of antibacterial properties in composite resin. Silver and zinc nanoparticles are considered to be broad-spectrum antibacterial agents. The aim of the present study was to evaluate the antibacterial properties of composite resins containing 1% silver and zinc-oxide nanoparticles on Streptococcus mutans and Lactobacillus. Materials and Methods Ninety discoid tablets containing 0%, 1% nano-silver and 1% nano zinc-oxide particles were prepa...

  9. The dynamic changes of the plasma membrane proteins and the protective roles of nitric oxide in rice subjected to heavy metal cadmium stress

    Directory of Open Access Journals (Sweden)

    Liming eYang

    2016-02-01

    Full Text Available The heavy metal cadmium is a common environmental contaminant in soils and has adverse effects on crop growth and development. The signaling processes in plants that initiate cellular responses to environmental stress have been shown to be located in the plasma membrane (PM. A better understanding of the PM proteome in response to environmental stress might provide new insights for improving stress-tolerant crops. Nitric oxide (NO is reported to be involved in the plant response to cadmium (Cd stress. To further investigate how NO modulates protein changes in the plasma membrane during Cd stress, a quantitative proteomics approach based on isobaric tags for relative and absolute quantification (iTRAQ was used to identify differentially regulated proteins from the rice plasma membrane after Cd or Cd and NO treatment. Sixty-six differentially expressed proteins were identified, of which, many function as transporters, ATPases, kinases, metabolic enzymes, phosphatases and phospholipases. Among these, the abundance of phospholipase D (PLD was altered substantially after the treatment of both Cd and Cd and NO. Transient expression of the PLD fused with green fluorescent peptide (GFP in rice protoplasts showed that the Cd and NO treatment promoted the accumulation of PLD in the plasma membrane. Addition of NO also enhanced Cd-induced PLD activity and the accumulation of phosphatidic acid (PA produced through PLD activity. Meanwhile, NO elevated the activities of antioxidant enzymes and caused the accumulation of glutathione both which function to reduce Cd-induced H2O2 accumulation. Taken together, we suggest that NO signaling is associated with the accumulation of antioxidant enzymes, glutathione and PA which increases cadmium tolerance in rice via the antioxidant defense system.

  10. Antibacterial properties of composite resins incorporating silver and zinc oxide nanoparticles on Streptococcus mutans and Lactobacillus

    Science.gov (United States)

    Kasraei, Shahin; Sami, Lida; Hendi, Sareh; AliKhani, Mohammad-Yousef; Rezaei-Soufi, Loghman

    2014-01-01

    Objectives Recurrent caries was partly ascribed to lack of antibacterial properties in composite resin. Silver and zinc nanoparticles are considered to be broad-spectrum antibacterial agents. The aim of the present study was to evaluate the antibacterial properties of composite resins containing 1% silver and zinc-oxide nanoparticles on Streptococcus mutans and Lactobacillus. Materials and Methods Ninety discoid tablets containing 0%, 1% nano-silver and 1% nano zinc-oxide particles were prepared from flowable composite resin (n = 30). The antibacterial properties of composite resin discs were evaluated by direct contact test. Diluted solutions of Streptococcus mutans (PTCC 1683) and Lactobacillus (PTCC 1643) were prepared. 0.01 mL of each bacterial species was separately placed on the discs. The discs were transferred to liquid culture media and were incubated at 37℃ for 8 hr. 0.01 mL of each solution was cultured on blood agar and the colonies were counted. Data was analyzed with Kruskall-Wallis and Mann-Whitney U tests. Results Composites containing nano zinc-oxide particles or silver nanoparticles exhibited higher antibacterial activity against Streptococcus mutans and Lactobacillus compared to the control group (p < 0.05). The effect of zinc-oxide on Streptococcus mutans was significantly higher than that of silver (p < 0.05). There were no significant differences in the antibacterial activity against Lactobacillus between composites containing silver nanoparticles and those containing zinc-oxide nanoparticles. Conclusions Composite resins containing silver or zinc-oxide nanoparticles exhibited antibacterial activity against Streptococcus mutans and Lactobacillus. PMID:24790923

  11. Behavior of incorporated nitrogen in plasma-nitrided silicon oxide formed by chemical vapor deposition

    Science.gov (United States)

    Shinoda, Nao; Itokawa, Hiroshi; Fujitsuka, Ryota; Sekine, Katsuyuki; Onoue, Seiji; Tonotani, Junichi

    2016-04-01

    The behavior of nitrogen (N) atoms in plasma-nitrided silicon oxide (SiO2) formed by chemical vapor deposition (CVD) was characterized by physical analysis and from electrical properties. The changes in the chemical bonding and distribution of N in plasma-nitrided SiO2 were investigated for different subsequent processes. N-Si3, N-Si2O, and N2 are formed in a SiO2 film by plasma nitridation. N2 molecules diffuse out during annealing at temperatures higher than 900 °C. NH species are generated from N2 molecules and H in the SiO2 film with subsequent oxide deposition using O3 as an oxidant. The capacitance-voltage (C-V) curves of metal-oxide-semiconductor (MOS) capacitors are obtained. The negative shift of the C-V curve is caused by the increase in the density of positive fix charge traps in CVD-SiO2 induced by plasma nitridation. The C-V curve of plasma-nitrided SiO2 subjected to annealing shifts to the positive direction and that subjected to the subsequent oxide deposition shifts markedly to the negative direction. It is clarified that the density of positive charge fixed traps in plasma-nitrided SiO2 films decrease because the amount of N2 molecules is decreased by annealing, and that the density of traps increases because NH species are generated and move to the interface between SiO2 and the Si substrate with the subsequent oxide deposition.

  12. Structure and properties of YBa2Cu3O7-δ superconductor doped with bulk cadmium oxide

    Directory of Open Access Journals (Sweden)

    A Echresh

    2010-09-01

    Full Text Available In this paper, the Y1-xCdxBa2Cu3O7-δ superconductor with x=0, 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5 are prepared using the solid state method and the structure, electrical resistance, critical current density and critical temperature of it, have been studied. The results show that these doping do not affect so much on the structure and lattice parameters. The electrical resistance of samples increased with doping. A little amount of doping cadmium improve critical current density such that the sample x=0.1 has a maximum critical current density among the samples. The critical temperature with doping cadmium up to x=0.2 has little fluctuation and its variation can be ignored, but by increasing up to x=0.5 the critical temperature decreases gradually.

  13. Incorporation, oxidation and pyrolysis of ferrocene into porous silica glass: a route to different silica/carbon and silica/iron oxide nanocomposites.

    Science.gov (United States)

    Schnitzler, Mariane C; Mangrich, Antônio S; Macedo, Waldemar A A; Ardisson, José D; Zarbin, Aldo J G

    2006-12-25

    This work reports the incorporation of ferrocene into a porous silica glass under ambient temperature and atmosphere. After or during the ferrocene incorporation, the spontaneous formation of ferricinium ions was observed by electron paramagnetic resonance (EPR), UV-visible, X-ray absorption near-edge structure (XANES), and 57Fe Mössbauer measurements. It was shown that the oxidation of ferrocene molecules to ferricinium ions was promoted by air and that the Si-O- groups on the surface of the pores act as counteranions. Pyrolysis of the porous glass/ferricinium material under argon atmosphere and variable temperature yields different glass/carbon nanocomposites, which were subsequently treated with an HF solution in order to remove the glassy fraction. The resulting insoluble carbon materials were characterized by transmission electron microscopy (TEM), Raman, and EPR spectroscopy and consisted of amorphous carbon when the pyrolysis was carried out at 900 or 1000 degrees C and of a mixture of carbon nanotubes and carbonaceous materials at a pyrolysis temperature of 1100 degrees C. When the pyrolysis was conducted under air, the incorporated ferricinium forms alpha-Fe2O3, and the resulting material is a transparent and highly homogeneous glass/iron oxide nanocomposite. PMID:17173419

  14. FrnE, a Cadmium-Inducible Protein in Deinococcus radiodurans, Is Characterized as a Disulfide Isomerase Chaperone In Vitro and for Its Role in Oxidative Stress Tolerance In Vivo

    OpenAIRE

    Khairnar, Nivedita P.; Joe, Min-Ho; Misra, H. S.; Lim, Sang-Yong; Kim, Dong-Ho

    2013-01-01

    Deinococcus radiodurans R1 exposed to a lethal dose of cadmium shows differential expression of a large number of genes, including frnE (drfrnE) and some of those involved in DNA repair and oxidative stress tolerance. The drfrnE::nptII mutant of D. radiodurans showed growth similar to that of the wild type, but its tolerance to 10 mM cadmium and 10 mM diamide decreased by ∼15- and ∼3-fold, respectively. These cells also showed nearly 6 times less resistance to gamma radiation at 12 kGy and ∼2...

  15. Electrochemical energy storage devices using electrodes incorporating carbon nanocoils and metal oxides nanoparticles

    KAUST Repository

    Baby, Rakhi Raghavan

    2011-07-28

    Carbon nanocoil (CNC) based electrodes are shown to be promising candidates for electrochemical energy storage applications, provided the CNCs are properly functionalized. In the present study, nanocrystalline metal oxide (RuO 2, MnO2, and SnO2) dispersed CNCs were investigated as electrodes for supercapacitor applications using different electrochemical methods. In the two electrode configuration, the samples exhibited high specific capacitance with values reaching up to 311, 212, and 134 F/g for RuO2/CNCs, MnO2/CNCs, and SnO2/CNCs, respectively. The values obtained for specific capacitance and maximum storage energy per unit mass of the composites were found to be superior to those reported for metal oxide dispersed multiwalled carbon nanotubes in two electrode configuration. In addition, the fabricated supercapacitors retained excellent cycle life with ∼88% of the initial specific capacitance retained after 2000 cycles. © 2011 American Chemical Society.

  16. An electrochemical dopamine aptasensor incorporating silver nanoparticle, functionalized carbon nanotubes and graphene oxide for signal amplification.

    Science.gov (United States)

    Bahrami, Shokoh; Abbasi, Amir Reza; Roushani, Mahmoud; Derikvand, Zohreh; Azadbakht, Azadeh

    2016-10-01

    In this work, immobilization of a dopamine (DA) aptamer was performed at the surface of an amino functionalized silver nanoparticle-carbon nanotube graphene oxide (AgNPs/CNTs/GO) nanocomposite. A 58-mer DA-aptamer was immobilized through the formation of phosphoramidate bonds between the amino group of chitosan and the phosphate group of the aptamer at the 5' end. An AgNPs/CNTs/GO nanocomposite was employed as a highly catalytic label for electrochemical detection of DA based on electrocatalytic activity of the nanocomposite toward hydrogen peroxide (H2O2). Interaction of DA with the aptamer caused conformational changes of the aptamer which, in turn, decreased H2O2 oxidation and reduction peak currents. On the other hand, the presumed folding of the DA-aptamer complexes on the sensing interface inhibited the electrocatalytic activity of AgNPs/CNTs/GO toward H2O2. Sensitive quantitative detection of DA was carried out by monitoring the decrease of differential pulse voltammetric (DPV) responses of AgNPs/CNTs/GO nanocomposite toward H2O2 oxidation. The DPV signal linearly decreased with increased concentration of DA from 3 to 110nmolL(-1) with a detection limit of 700±19.23pmolL(-1). Simple preparation, low operation cost, speed and validity are the decisive factors of this method motivating its application to biosensing investigation. PMID:27474313

  17. Arsenate sorption by hydrous ferric oxide incorporated onto granular activated carbon with phenol formaldehyde resins coating.

    Science.gov (United States)

    Zhuang, J M; Hobenshield, E; Walsh, T

    2008-04-01

    A simple and effective method was developed using phenol formaldehyde (PF) resins to immobilize hydrous ferric oxide (HFO) onto granular activated carbon (GAC). The resulting sorbent possesses advantages for both the ferric oxide and the GAC, such as a great As-affinity of ferric oxide, large surface area of GAC, and enhanced physical strength. The studies showed that within one hour this sorbent was able to remove 85% of As(V) from water containing an initial As(V) concentration of 1.74 mg l(-1). The As(V) adsorption onto the sorbent was found to follow a pseudo-second order kinetics model. The adsorption isotherms were interpreted in terms of the Langmuir and Freundlich models. The equilibrium data fitted very well to both models. Column tests showed that this sorbent was able to achieve residual concentrations of As(V) in a range of 0.1-2.0 microg l(-1) while continuously treating about 180 bed volume (BV, 130 ml-BV) of arsenate water with an initial As(V) concentration of 1886 microg l(-1) at a filtration rate of 13.5 ml min(-1), i.e., an empty bed contact time (EBCT) of 9.6 min and a gram sorbent contact time (GSCT) of 0.15 min. After passing 635 BV of arsenate water, the exhausted sorbent was then tested by the Toxicity Characteristic Leaching Procedure (TCLP, US EPA Method 1311) test, and classified as non-hazardous for disposal. Hence, this HFO-PF-coated GAC has the capability to remove As(V) from industrial wastewater containing As(V) levels of about 2 mg l(-1).

  18. Passivation of oxide traps and interface states in GaAs metal-oxide-semiconductor capacitor by LaTaON passivation layer and fluorine incorporation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, L. N.; Choi, H. W.; Lai, P. T., E-mail: laip@eee.hku.hk [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong); Xu, J. P. [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-11-23

    GaAs metal-oxide-semiconductor capacitor with TaYON/LaTaON gate-oxide stack and fluorine-plasma treatment is fabricated and compared with its counterparts without the LaTaON passivation interlayer or the fluorine treatment. Experimental results show that the sample exhibits better characteristics: low interface-state density (8 × 10{sup 11 }cm{sup −2}/eV), small flatband voltage (0.69 V), good capacitance-voltage behavior, small frequency dispersion, and small gate leakage current (6.35 × 10{sup −6} A/cm{sup 2} at V{sub fb} + 1 V). These should be attributed to the suppressed growth of unstable Ga and As oxides on the GaAs surface during gate-oxide annealing by the LaTaON interlayer and fluorine incorporation, and the passivating effects of fluorine atoms on the acceptor-like interface and near-interface traps.

  19. Passivation of oxide traps and interface states in GaAs metal-oxide-semiconductor capacitor by LaTaON passivation layer and fluorine incorporation

    International Nuclear Information System (INIS)

    GaAs metal-oxide-semiconductor capacitor with TaYON/LaTaON gate-oxide stack and fluorine-plasma treatment is fabricated and compared with its counterparts without the LaTaON passivation interlayer or the fluorine treatment. Experimental results show that the sample exhibits better characteristics: low interface-state density (8 × 1011 cm−2/eV), small flatband voltage (0.69 V), good capacitance-voltage behavior, small frequency dispersion, and small gate leakage current (6.35 × 10−6 A/cm2 at Vfb + 1 V). These should be attributed to the suppressed growth of unstable Ga and As oxides on the GaAs surface during gate-oxide annealing by the LaTaON interlayer and fluorine incorporation, and the passivating effects of fluorine atoms on the acceptor-like interface and near-interface traps

  20. Cadmium Stabilization Efficiency and Leachability by CdAl4O7 Monoclinic Structure.

    Science.gov (United States)

    Su, Minhua; Liao, Changzhong; Chuang, Kui-Hao; Wey, Ming-Yen; Shih, Kaimin

    2015-12-15

    This study investigated the stabilization efficiencies of using an aluminum-rich precursor to incorporate simulated cadmium-bearing waste sludge and evaluated the leaching performance of the product phase. Cadmium oxide and γ-alumina mixtures with various Cd/Al molar ratios were fired at 800-1000 °C for 3 h. Cadmium could be crystallochemically incorporated by γ-alumina into CdAl4O7 monoclinic phase and the reaction was strongly controlled by the treatment temperature. The crystal structure details of CdAl4O7 were solved and refined with the Rietveld refinement method. According to the structural refinement results, the stabilization efficiencies were quantified and expressed as a transformation ratio (TR) with optimized processing parameters. The preferred treatment temperature was found to be 950 °C for mixtures with a Cd/Al molar ratio of 1/4, as its TR value indicated the cadmium incorporation was nearly completed after a 3 h treatment scheme. Constant-pH leaching tests (CPLT) were conducted by comparing the leachability of the CdO and CdAl4O7 phases in a pH 4.0 environment. A remarkable reduction in cadmium leachability could be achieved via monoclinic CdAl4O7 structure formation to effectively stabilize hazardous cadmium in the waste stream. The CPLT and X-ray photoelectron spectroscopy (XPS) results suggested incongruent dissolution behavior during the leaching of the CdAl4O7 phase. PMID:26512873

  1. Enhanced optical properties due to indium incorporation in zinc oxide nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Farid, S.; Mukherjee, S.; Sarkar, K.; Mazouchi, M. [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Stroscio, M. A. [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Dutta, M., E-mail: dutta@uic.edu [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)

    2016-01-11

    Indium-doped zinc oxide nanowires grown by vapor-liquid-solid technique with 1.6 at. % indium content show intense room temperature photoluminescence (PL) that is red shifted to 20 meV from band edge. We report on a combination of nanowires and nanobelts-like structures with enhanced optical properties after indium doping. The near band edge emission shift gives an estimate for the carrier density as high as 5.5 × 10{sup 19 }cm{sup −3} for doped nanowires according to Mott's critical density theory. Quenching of the visible green peak is seen for doped nanostructures indicating lesser oxygen vacancies and improved quality. PL and transmission electron microscopy measurements confirm indium doping into the ZnO lattice, whereas temperature dependent PL data give an estimation of the donor and acceptor binding energies that agrees well with indium doped nanowires. This provides a non-destructive technique to estimate doping for 1D structures as compared to the traditional FET approach. Furthermore, these indium doped nanowires can be a potential candidate for transparent conducting oxides applications and spintronic devices with controlled growth mechanism.

  2. Enhanced optical properties due to indium incorporation in zinc oxide nanowires

    International Nuclear Information System (INIS)

    Indium-doped zinc oxide nanowires grown by vapor-liquid-solid technique with 1.6 at. % indium content show intense room temperature photoluminescence (PL) that is red shifted to 20 meV from band edge. We report on a combination of nanowires and nanobelts-like structures with enhanced optical properties after indium doping. The near band edge emission shift gives an estimate for the carrier density as high as 5.5 × 1019 cm−3 for doped nanowires according to Mott's critical density theory. Quenching of the visible green peak is seen for doped nanostructures indicating lesser oxygen vacancies and improved quality. PL and transmission electron microscopy measurements confirm indium doping into the ZnO lattice, whereas temperature dependent PL data give an estimation of the donor and acceptor binding energies that agrees well with indium doped nanowires. This provides a non-destructive technique to estimate doping for 1D structures as compared to the traditional FET approach. Furthermore, these indium doped nanowires can be a potential candidate for transparent conducting oxides applications and spintronic devices with controlled growth mechanism

  3. Enhanced optical properties due to indium incorporation in zinc oxide nanowires

    Science.gov (United States)

    Farid, S.; Mukherjee, S.; Sarkar, K.; Mazouchi, M.; Stroscio, M. A.; Dutta, M.

    2016-01-01

    Indium-doped zinc oxide nanowires grown by vapor-liquid-solid technique with 1.6 at. % indium content show intense room temperature photoluminescence (PL) that is red shifted to 20 meV from band edge. We report on a combination of nanowires and nanobelts-like structures with enhanced optical properties after indium doping. The near band edge emission shift gives an estimate for the carrier density as high as 5.5 × 1019 cm-3 for doped nanowires according to Mott's critical density theory. Quenching of the visible green peak is seen for doped nanostructures indicating lesser oxygen vacancies and improved quality. PL and transmission electron microscopy measurements confirm indium doping into the ZnO lattice, whereas temperature dependent PL data give an estimation of the donor and acceptor binding energies that agrees well with indium doped nanowires. This provides a non-destructive technique to estimate doping for 1D structures as compared to the traditional FET approach. Furthermore, these indium doped nanowires can be a potential candidate for transparent conducting oxides applications and spintronic devices with controlled growth mechanism.

  4. Improved performance of CdS/CdSe quantum dots sensitized solar cell by incorporation of ZnO nanoparticles/reduced graphene oxide nanocomposite as photoelectrode

    Science.gov (United States)

    Ghoreishi, F. S.; Ahmadi, V.; Samadpour, M.

    2014-12-01

    Here we present novel quantum dot sensitized solar cells (QDSSC) based on ZnO nanoparticles (NPs)/reduced graphene oxide (RGO) nanocomposite photoanodes for better light harvesting and energy conversion. Photoelectrodes are prepared by doctor blading ZnO NPs/GO nanocomposite paste on a fluorine doped tin oxide substrate which are then sintered at 450 °C to obtain ZnO NPs/RGO nanocomposites. The partial reduction of GO after thermal reduction, is studied by Fourier transform infrared and Raman spectroscopies. Cadmium sulfide (CdS) and cadmium selenide (CdSe) quantum dots are deposited on the films through successive ionic layer adsorption and reaction and chemical bath deposition methods, respectively. The unique properties of ZnO NPs/RGO photoanodes, lead to a significant enhancement in the photovoltaic properties of solar cells in comparison with bare ZnO photoanodes. Current-voltage characteristics of cells are studied and the best results are obtained from ZnO NPs-RGO/CdS/CdSe with photoelectric conversion efficiency of 2.20% which is almost two times higher than cells which are made by pure ZnO NPs as photoanode (1.28%). Electrochemical impedance measurements show that the enhancement can be attributed to the increase of electron transfer rate in the ZnO NPs/RGO nanocomposite photoanode which arises from the ultrahigh electron mobility in graphene (RGO) sheets.

  5. Effect of incorporation of reduced graphene oxide on ZnO-based dye-sensitized solar cells

    Science.gov (United States)

    Song, Jun-Ling; Wang, Xiu

    2016-07-01

    Here, we demonstrate a facile method to improve the cell performance of ZnO-based dye sensitized solar cell by incorporating different amount of reduced graphene oxide (rGO). Overall photo-to-current conversion-efficiency (PCE) of the device 3 with 0.75 mL rGO exhibits a 1.3 times improvement compared to bare ZnO. The electrochemical impedance spectroscopy (EIS) measurements show that the enhancement could be attributed to the improvement of electron transport/injection and the decrease of the charge recombination in the device, which arise from the formation of rGO-based Schottky junction in ZnO-photoanode.

  6. Superparamagnetic iron oxide nanoparticles incorporated into silica nanoparticles by inelastic collision via ultrasonic field: Role of colloidal stability

    Energy Technology Data Exchange (ETDEWEB)

    Sodipo, Bashiru Kayode; Azlan, Abdul Aziz [Nano-Optoelectronics Research and Technology (NOR) Lab, School of Physics, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia Nano-Biotechnology Research (Malaysia); Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang (Malaysia)

    2015-04-24

    Superparamagnetic iron oxide nanoparticles (SPION)/Silica composite nanoparticles were prepared by ultrasonically irradiating colloidal suspension of silica and SPION mixture. Both silica and SPION were synthesized independently via co-precipitation and sol-gel method, respectively. Their mixtures were sonicated at different pH between 3 and 5. Electrophoresis measurement and other physicochemical analyses of the products demonstrate that at lower pH SPION was found incorporated into the silica. However, at pH greater than 4, SPION was unstable and unable to withstand the turbulence flow and shock wave from the ultrasonic field. Results suggest that the formation of the SPION/silica composite nanoparticles is strongly related to the inelastic collision induced by ultrasonic irradiation. More so, the formation the composite nanoparticles via the ultrasonic field are dependent on the zeta potential and colloidal stability of the particles.

  7. Effects of straw incorporation along with microbial inoculant on methane and nitrous oxide emissions from rice fields.

    Science.gov (United States)

    Liu, Gang; Yu, Haiyang; Ma, Jing; Xu, Hua; Wu, Qinyan; Yang, Jinghui; Zhuang, Yiqing

    2015-06-15

    Incorporation of straw together with microbial inoculant (a microorganism agent, accelerating straw decomposition) is being increasingly adopted in rice cultivation, thus its effect on greenhouse gas (GHG) emissions merits serious attention. A 3-year field experiment was conducted from 2010 to 2012 to investigate combined effect of straw and microbial inoculant on methane (CH4) and nitrous oxide (N2O) emissions, global warming potential (GWP) and greenhouse gas intensity (GHGI) in a rice field in Jurong, Jiangsu Province, China. The experiment was designed to have treatment NPK (N, P and K fertilizers only), treatment NPKS (NPK plus wheat straw), treatment NPKSR (NPKS plus Ruilaite microbial inoculant) and treatment NPKSJ (NPKS plus Jinkuizi microbial inoculant). Results show that compared to NPK, NPKS increased seasonal CH4 emission by 280-1370%, while decreasing N2O emission by 7-13%. When compared with NPKS, NPKSR and NPKSJ increased seasonal CH4 emission by 7-13% and 6-12%, respectively, whereas reduced N2O emission by 10-27% and 9-24%, respectively. The higher CH4 emission could be attributed to the higher soil CH4 production potential triggered by the combined application of straw and microbial inoculant, and the lower N2O emission to the decreased inorganic N content. As a whole, the benefit of lower N2O emission was completely offset by increased CH4 emission, resulting in a higher GWP for NPKSR (5-12%) and NPKSJ (5-11%) relative to NPKS. Due to NPKSR and NPKSJ increased rice grain yield by 3-6% and 2-4% compared to NPKS, the GHGI values for NPKS, NPKSR and NPKSJ were comparable. These findings suggest that incorporating straw together with microbial inoculant would not influence the radiative forcing of rice production in the terms of per unit of rice grain yield relative to the incorporation of straw alone. PMID:25756676

  8. Incorporating biodegradation and advanced oxidation processes in the treatment of spent metalworking fluids.

    Science.gov (United States)

    MacAdam, Jitka; Ozgencil, Haci; Autin, Olivier; Pidou, Marc; Temple, Clive; Parsons, Simon; Jefferson, Bruce

    2012-12-01

    The treatment of spent metalworking fluids (MWFs) is difficult due to their complex and variable composition. Small businesses often struggle to meet increasingly stringent legislation and rising costs as they need to treat this wastewater on site annually over a short period. Larger businesses that treat their wastewater continuously can benefit from the use of biological processes, although new MWFs designed to resist biological activity represent a challenge. A three-stage treatment is generally applied, with the oil phase being removed first, followed by a reduction in COD loading and then polishing of the effluent's quality in the final stage. The performance of advanced oxidation processes (AOPs), which could be of benefit to both types of businesses was studied. After assessing the biodegradability of spent MFW, different AOPs were used (UV/H2O2, photo-Fenton and UV/TiO2) to establish the treatability of this wastewater by hydroxyl radicals (*OH). The interactions of both the chemical and biological treatments were also investigated. The wastewater was found to be readily biodegradable in the Zahn-Wellens test with 69% COD and 74% DOC removal. The UV/TiO2 reactor was found to be the cheapest option achieving a very good COD removal (82% at 20 min retention time and 10 L min(-1) aeration rate). The photo-Fenton process was found to be efficient in terms of degradation rate, achieving 84% COD removal (1 M Fe2+, 40 M H2O2, 20.7 J cm(-2), pH 3) and also improving the wastewater's biodegradability. The UV/H202 process was the most effective in removing recalcitrant COD in the post-biological treatment stage. PMID:23437675

  9. Critical review of animal carcinogenesis by cadmium and its inorganic compounds

    International Nuclear Information System (INIS)

    Animal carcinogenic biassays relative to 6 inorganic cadmium substances (cadmium metal, cadmium oxide, cadmium sulfide, cadmium sulfate, cadmium chloride and cadmium acetate) are reviewed (speciation). Critical evaluation of literature data on carcinogenicity has been performed by making reference to E.C. guidelines of good laboratory practice. There are few data on routes relevant for human risk assessment: experiments on inhalation demonstrate lung carcinogenicity of cadmium oxide, cadmium sulfide, cadmium sulfate and cadmium chloride in rats but not in mice nor in hamsters; no carcinogenic effects of cadmium compounds are observed following oral administration. For routes of less or no relevance for human risk assessment, some results are clearly positive: subcutaneous injection induces cancers in situ (various cadmium compounds), testicular tumours (cadmium sulfate and cadmium chloride) and prostatic tumours (cadmium chloride) but such effects are not observed using relevant malignancies in rats. With respect to other no relevant routes (intraperitoneal, intrarenal...) tumours are incidentally produced in situ, but not in remote organs. Numerous studies fail to demonstrate cadmium carcinogenicity, but methodologically acceptable negative ones are very limited in number. Accordingly strain dependent effects and dose effect relationship could not be thoroughly assessed

  10. Protective effect of zinc supplementation against cadmium-induced oxidative stress and the RANK/RANKL/OPG system imbalance in the bone tissue of rats

    Energy Technology Data Exchange (ETDEWEB)

    Brzóska, Malgorzata M., E-mail: Malgorzata.Brzoska@umb.edu.pl; Rogalska, Joanna

    2013-10-01

    It was investigated whether protective influence of zinc (Zn) against cadmium (Cd)-induced disorders in bone metabolism may be related to its antioxidative properties and impact on the receptor activator of nuclear factor (NF)-κΒ (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system. Numerous indices of oxidative/antioxidative status, and Cd and Zn were determined in the distal femur of the rats administered Zn (30 and 60 mg/l) or/and Cd (5 and 50 mg/l) for 6 months. Soluble RANKL (sRANKL) and OPG were measured in the bone and serum. Zn supplementation importantly protected from Cd-induced oxidative stress preventing protein, DNA, and lipid oxidation in the bone. Moreover, Zn protected from the Cd-induced increase in sRANKL concentration and the sRANKL/OPG ratio, and decrease in OPG concentration in the bone and serum. Numerous correlations were noted between indices of the oxidative/antioxidative bone status, concentrations of sRANKL and OPG in the bone and serum, as well as the bone concentrations of Zn and Cd, and previously reported by us in these animals (Brzóska et al., 2007) indices of bone turnover and bone mineral density. The results allow us to conclude that the ability of Zn to prevent from oxidative stress and the RANK/RANKL/OPG system imbalance may be implicated in the mechanisms of its protective impact against Cd-induced bone damage. This paper is the first report from an in vivo study providing evidence that beneficial Zn impact on the skeleton under exposure to Cd is related to the improvement of the bone tissue oxidative/antioxidative status and mediating the RANK/RANKL/OPG system. - Highlights: • Cd induces oxidative stress in the bone tissue. • Cd disturbs bone metabolism via disorder of the RANK/RANKL/OPG system balance. • Zn supplementation protects from Cd-induced oxidative stress in the bone tissue. • Zn protects from the RANK/RANKL/OPG system imbalance caused by Cd in the bone tissue. • Enhanced Zn intake protects from Cd

  11. A MEMS based acetone sensor incorporating ZnO nanowires synthesized by wet oxidation of Zn film

    International Nuclear Information System (INIS)

    In this work, we report a simple and efficient method for synthesis of ZnO nanowires by thermal oxidation of Zn film and their integration with MEMS technologies to fabricate a sensor for acetone vapour detection. ZnO nanowires were prepared by thermal oxidation of sputter deposited Zn film. The nanostructured ZnO was characterized by x-ray diffraction, a scanning electron microscope and room temperature photoluminescence measurements. The ZnO nanowires synthesis process was integrated with MEMS technologies to obtain a sensor for volatile organic compounds, incorporating an on-chip Ni microheater and an interdigited electrode structure. To reduce the heat loss from the on-chip microheater, the sensor was made on a thin silicon diaphragm obtained via a modified reactive ion etching process. This resulted in considerable power saving during sensor operation. For this, a three-mask process was used. The performance of the microheater was simulated on COMSOL and validated experimentally. The sensor has been tested for acetone vapour sensing and the operating parameters were optimized. The sensor has the ability to detect acetone vapour at 5 parts per million (ppm) concentrations when operated at 100 °C. The sensor consumed only 36 mW power and showed a high-sensitivity value of 26.3% for 100 ppm of acetone vapour. (paper)

  12. Non-covalent functionalization of graphene oxide by polyindole and subsequent incorporation of Ag nanoparticles for electrochemical applications

    Science.gov (United States)

    Dubey, Prashant; Kumar, Ashish; Prakash, Rajiv

    2015-11-01

    Reduced graphene oxide (r-GO) sheets have been modified by polyindole (PIn) via in situ chemical oxidation method to obtain stable dispersion in water and furthermore incorporation of Ag nanoparticles (Ag NPs); the resulting Ag NPs/PIn-r-GO nanocomposite is demonstrated for electrochemical applications. Ag NPs/r-GO and PIn/GO nanocomposites have also been prepared for its comparative study with Ag NPs/PIn-r-GO. Non-covalent functionalization of GO by PIn polymer leads to PIn-GO dispersion, which is stable for several months without any precipitation. This dispersed solution is used for formation of Ag NPs/PIn-r-GO nanocomposite. Various experimental tools like UV-vis, FTIR and TEM have been used to characterize as-synthesized materials. Thereafter electrochemical performance of as-synthesized nanocomposites have been compared for their charge capacitive behaviour (without its poisoning compared to Ag NPs/r-GO) which leads to be an excellent candidate for the possible applications such as electrocatalysis, charge storage devices, etc. We observed that Ag NPs/PIn-r-GO nanocomposite exhibits better processability and electroactivity as electrode material in comparison to Ag NPs/r-GO and PIn/GO nanocomposites due to synergistic effect of individual components.

  13. Incorporation of Hydrogen Bonding Functionalities into the Second Coordination Sphere of Iron-Based Water Oxidation Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hoffert, Wesley A.; Mock, Michael T.; Appel, Aaron M.; Yang, Jenny Y.

    2013-08-06

    Energy storage and conversion schemes based on environmentally benign chemical fuels will require the discovery of faster, cheaper, and more robust catalysts for the oxygen evolution reaction (OER). Although pendant bases have led to enhanced turnover frequencies with non-aqueous substrates, their effect on the catalytic behavior of molecular water oxidation catalysts has received little attention. Herein, the syntheses, structures, and catalytic activities of new iron complexes with pendant bases are reported. Of these, the complex [Fe(mepydz)4(CH3CN)2](OTf)2 (mepydz = N,N'-dimethyl-N,N'-bis(pyridazin-3-ylmethyl)ethane-1,2-diamine, OTf = trifluoromethanesulonate) (8(CH3CN)22+) is the most active catalyst. Initial turnover frequencies of 141 h-1 and 24 h-1 were measured using ceric ammonium nitrate at pH 0.7 and sodium periodate at pH 4.7, respectively. At pH 4.7, 8(CH3CN)22+ the initial turnover frequency is 70% faster than the structurally analogous complex without ancillary proton relays. These results demonstrate that the incorporation of pendant bases into molecular water oxidation catalysts is a synthetic principle that should be considered in the development of new OER catalysts. This work was supported by Laboratory Directed Research and Development program at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for the US Department of Energy.

  14. A MEMS based acetone sensor incorporating ZnO nanowires synthesized by wet oxidation of Zn film

    Science.gov (United States)

    Behera, Bhagaban; Chandra, Sudhir

    2015-01-01

    In this work, we report a simple and efficient method for synthesis of ZnO nanowires by thermal oxidation of Zn film and their integration with MEMS technologies to fabricate a sensor for acetone vapour detection. ZnO nanowires were prepared by thermal oxidation of sputter deposited Zn film. The nanostructured ZnO was characterized by x-ray diffraction, a scanning electron microscope and room temperature photoluminescence measurements. The ZnO nanowires synthesis process was integrated with MEMS technologies to obtain a sensor for volatile organic compounds, incorporating an on-chip Ni microheater and an interdigited electrode structure. To reduce the heat loss from the on-chip microheater, the sensor was made on a thin silicon diaphragm obtained via a modified reactive ion etching process. This resulted in considerable power saving during sensor operation. For this, a three-mask process was used. The performance of the microheater was simulated on COMSOL and validated experimentally. The sensor has been tested for acetone vapour sensing and the operating parameters were optimized. The sensor has the ability to detect acetone vapour at 5 parts per million (ppm) concentrations when operated at 100 °C. The sensor consumed only 36 mW power and showed a high-sensitivity value of 26.3% for 100 ppm of acetone vapour.

  15. Graphene oxide-incorporated pH-responsive folate-albumin-photosensitizer nanocomplex as image-guided dual therapeutics.

    Science.gov (United States)

    Battogtokh, Gantumur; Ko, Young Tag

    2016-07-28

    The objective of this study was to develop an active-targeted, pH-responsive albumin-photosensitizer-incorporated graphene oxide nanocomplex as an image-guided theranostic agent for dual therapies. Herein, bovine serum albumin (BSA)-cis-aconityl pheophorbide-a (c-PheoA) conjugate was complexed with graphene oxide (GO) at ratios of 1:1, 1:0.5, and 1:0.1 with the mean hydrodynamic diameter of the resulting complex being 100-200nm. Further, with the 1:0.5 ratio, we developed a folate-BSA-c-PheoA conjugate:GO complex incorporated free PheoA (PheoA+GO:FA-BSA-c-PheoA NC) with a mean hydrodynamic diameter of 182.0±33.2nm. The release study showed that the photosensitizer from the nanocomplex was released rapidly at pH5.5 compared to that at pH7.4 when incubated for 24h. Cellular uptake results showed that the PheoA+GO:FA-BSA-c-PheoA NCs was readily taken up by B16F10 and MCF7 cancer cells. In vitro phototoxicity results showed that PheoA+GO:FA-BSA-c-PheoA NC has a higher efficacy against cancer cells than free PheoA, thereby demonstrating the synergistic effect of PS and GO in response to a single laser of 670nm. In vivo and ex vivo bioimaging results showed that fluorescence signals of higher intensity were observed in the tumor area of mice treated with PheoA+GO:FA-BSA-c-PheoA NC than those in the tumor of mice treated with free PheoA, thereby suggesting that the targeted nanocomplex selectively accumulated in the tumor area compared to free PheoA. Through antitumor study, PheoA+GO:FA-BSA-c-PheoA NC showed a synergistic effect in tumor-bearing mice by a single 671nm laser treatment. These results demonstrate that our prepared PheoA+GO:FA-BSA-c-PheoA NC can be used as a theranostic agent in phototherapies and for the photodiagnosis of cancer. PMID:27164545

  16. Effects of straw incorporation along with microbial inoculant on methane and nitrous oxide emissions from rice fields

    International Nuclear Information System (INIS)

    Incorporation of straw together with microbial inoculant (a microorganism agent, accelerating straw decomposition) is being increasingly adopted in rice cultivation, thus its effect on greenhouse gas (GHG) emissions merits serious attention. A 3-year field experiment was conducted from 2010 to 2012 to investigate combined effect of straw and microbial inoculant on methane (CH4) and nitrous oxide (N2O) emissions, global warming potential (GWP) and greenhouse gas intensity (GHGI) in a rice field in Jurong, Jiangsu Province, China. The experiment was designed to have treatment NPK (N, P and K fertilizers only), treatment NPKS (NPK plus wheat straw), treatment NPKSR (NPKS plus Ruilaite microbial inoculant) and treatment NPKSJ (NPKS plus Jinkuizi microbial inoculant). Results show that compared to NPK, NPKS increased seasonal CH4 emission by 280–1370%, while decreasing N2O emission by 7–13%. When compared with NPKS, NPKSR and NPKSJ increased seasonal CH4 emission by 7–13% and 6–12%, respectively, whereas reduced N2O emission by 10–27% and 9–24%, respectively. The higher CH4 emission could be attributed to the higher soil CH4 production potential triggered by the combined application of straw and microbial inoculant, and the lower N2O emission to the decreased inorganic N content. As a whole, the benefit of lower N2O emission was completely offset by increased CH4 emission, resulting in a higher GWP for NPKSR (5–12%) and NPKSJ (5–11%) relative to NPKS. Due to NPKSR and NPKSJ increased rice grain yield by 3–6% and 2–4% compared to NPKS, the GHGI values for NPKS, NPKSR and NPKSJ were comparable. These findings suggest that incorporating straw together with microbial inoculant would not influence the radiative forcing of rice production in the terms of per unit of rice grain yield relative to the incorporation of straw alone. - Highlights: • This paper presents 3-year measurements of CH4 and N2O emissions from a rice system. • Applying straw along

  17. Effects of straw incorporation along with microbial inoculant on methane and nitrous oxide emissions from rice fields

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gang; Yu, Haiyang [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Jing [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008 (China); Xu, Hua, E-mail: hxu@issas.ac.cn [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008 (China); Wu, Qinyan; Yang, Jinghui; Zhuang, Yiqing [Zhenjiang Institute of Agricultural Science of Hilly Regions in Jiangsu, Jurong 212400 (China)

    2015-06-15

    Incorporation of straw together with microbial inoculant (a microorganism agent, accelerating straw decomposition) is being increasingly adopted in rice cultivation, thus its effect on greenhouse gas (GHG) emissions merits serious attention. A 3-year field experiment was conducted from 2010 to 2012 to investigate combined effect of straw and microbial inoculant on methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) emissions, global warming potential (GWP) and greenhouse gas intensity (GHGI) in a rice field in Jurong, Jiangsu Province, China. The experiment was designed to have treatment NPK (N, P and K fertilizers only), treatment NPKS (NPK plus wheat straw), treatment NPKSR (NPKS plus Ruilaite microbial inoculant) and treatment NPKSJ (NPKS plus Jinkuizi microbial inoculant). Results show that compared to NPK, NPKS increased seasonal CH{sub 4} emission by 280–1370%, while decreasing N{sub 2}O emission by 7–13%. When compared with NPKS, NPKSR and NPKSJ increased seasonal CH{sub 4} emission by 7–13% and 6–12%, respectively, whereas reduced N{sub 2}O emission by 10–27% and 9–24%, respectively. The higher CH{sub 4} emission could be attributed to the higher soil CH{sub 4} production potential triggered by the combined application of straw and microbial inoculant, and the lower N{sub 2}O emission to the decreased inorganic N content. As a whole, the benefit of lower N{sub 2}O emission was completely offset by increased CH{sub 4} emission, resulting in a higher GWP for NPKSR (5–12%) and NPKSJ (5–11%) relative to NPKS. Due to NPKSR and NPKSJ increased rice grain yield by 3–6% and 2–4% compared to NPKS, the GHGI values for NPKS, NPKSR and NPKSJ were comparable. These findings suggest that incorporating straw together with microbial inoculant would not influence the radiative forcing of rice production in the terms of per unit of rice grain yield relative to the incorporation of straw alone. - Highlights: • This paper presents 3-year measurements of CH

  18. Anti-oxidative feedback and biomarkers in the intertidal seagrass Zostera japonica induced by exposure to copper, lead and cadmium.

    Science.gov (United States)

    Lin, Haiying; Sun, Tao; Zhou, Yi; Zhang, Xiaomei

    2016-08-15

    To investigate the potential influences of anthropogenic pollutants, we evaluated the responses of the intertidal seagrass Zostera japonica to three heavy metals: copper (Cu), lead (Pb), and cadmium (Cd). Z. japonica was exposed to various concentrations of Cu, Pb, and Cd (0, 0.5, 5, 50μM) over seven days. The effects were then analyzed using the antioxidant enzyme catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione peroxidase (GPX), and lipid peroxidation measured using malondialdehyde (MDA) as proxy. Metal accumulation in the above-ground tissues and phenotypic changes were also investigated. Our results revealed that heavy metal concentration increased in seagrass exposed to high levels of metals. Z. japonica has great potential for metal accumulation and a suitable candidate for the decontamination of moderately Cu contaminated bodies of water and can also potentially enhanced efforts of environmental decontamination, either through phytoextraction abilities or by functioning as an indicator for monitoring programs that use SOD, CAT, GPX, POD and MDA as biomarkers. PMID:27287861

  19. Protective effects of Artocarpus altilis (Moraceae) on cadmium-induced changes in sperm characteristics and testicular oxidative damage in rats.

    Science.gov (United States)

    Adaramoye, O A; Akanni, O O

    2016-03-01

    Cadmium (Cd) is a major environmental toxicant and an endocrine disruptor. We investigated the protective effects of methanol extract of Artocarpus altilis (AA) against Cd-induced testicular damage in rats while quercetin (Que) served as standard. The total flavonoids and phenolic contents (TFC and TPC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH) radicals scavenging activities of AA were determined. In vivo, thirty male Wistar rats were assigned to six groups and orally treated with corn oil (control), Cd alone, Cd+Que, Cd+AA, Que and AA alone. Que and AA were given at doses of 25 and 200 mg kg(-1), respectively, for 3 weeks and challenged with two doses of Cd (1.5 mg kg(-1)). Results showed that TFC and TPC of AA increased with increase in concentration. AA scavenged DPPH and OH radicals in a dose-dependent manner. Administration of Cd significantly increased the relative weight of testis of rats. Lipid peroxidation was significantly increased while antioxidant parameters decreased in testis of Cd-treated rats. Also, Cd-treated rats had significantly reduced sperm count, motility, sialic acid, luteinising hormone and testosterone relative to controls. Pre-treatment with AA or Que significantly attenuated the biochemical alterations observed in Cd-treated rats. Overall, AA protects against Cd-induced testicular damage via antioxidative mechanism.

  20. Synthesis and characterization of inorganic ion exchangers based on mixed oxide tin-titanium to be used in recovery of cadmium and nickel and photoluminescent studies

    International Nuclear Information System (INIS)

    This work presents the synthesis, characterization and adsorption studies of inorganic ion exchangers based on mixed tin-titanium oxide for recovery of cadmium and nickel metals from aqueous effluents, discarded in the environment mainly through Ni-Cd battery. The exchangers were synthesized by sol-gel modified method using a mixture of tin(IV) chloride and titanium(III) chloride and ammonium hydroxide, as precursors reagents. The materials obtained: SnO2/TiO2 and SnO2/TiO2:Eu3+ were characterized by infrared spectroscopy, thermal analysis, scattering electronic microscopy (SEM), X-ray powder diffraction (XRD) (powder method) and electronic spectroscopy (excitation and emission) for the europium doped exchanger. The same materials also were synthesized in polymeric matrix too and can be used in column, because the synthesized materials showed crystals size in nano metric scale. It was determined by the distribution ratios for metals taking as parameters the influence of pH, the concentration of metals (by adsorption isotherms) and the contact time (by adsorption kinetic). The inorganic ion exchanger presented high exchange capacity with adsorption percent above 90 por cent for the studied conditions, quickly kinetic, heterogeneous exchange surfaces, physic adsorption and spontaneous process of exchange. To the doped exchanger spectroscopy properties were studied and also it was calculated the intensity parameters and it was found a satisfactory quantum yield. (author)

  1. Effect of Nanosized Tin Oxide Layer on the Efficiency of Photovoltaic Processes in Film Solar Cells Based on Cadmium Telluride

    Directory of Open Access Journals (Sweden)

    G.S. Khrypunov

    2015-03-01

    Full Text Available The influence of the thickness of the nanosized layer on the efficiency of photoelectric processes in solar cells (SC ITO / SnO2 / CdS / CdTe / Cu / Au formed on different substrates was investigated. For device structures formed on the glass substrates, the maximum efficiency of 11.4 % is achieved when thickness of the tin oxide layer is 80 nm. For flexible solar cells formed on a polyimide film, the maximum efficiency of 10.8 % is observed when thickness of the tin oxide layer is 50 nm. This paper discusses the physical mechanisms of the observed differences in efficiency.

  2. Oxidative stress response in Arabidopsis thaliana roots and leaves exposed to cadmium, uranium or a combination of both stressors

    Energy Technology Data Exchange (ETDEWEB)

    Horemans, N.; Saenen, E.; Vandenhove, H. [Belgian Nuclear Research Centre, SCK.CEN, Boeretang 200, 2400 Mol (Belgium); Hendrix, S.; Keunen, E.; Cuypers, A. [Hasselt University, Centre for Environmental Sciences, Agoralaan, Building D, 3590 Diepenbeek (Belgium)

    2014-07-01

    Nuclear energy production or NORM industry released low amounts of radioactive substances together with non-radioactive substances (e.g., heavy metals, organic chemicals) to the environment. As sessile organisms, plants are commonly exposed to a number of adverse conditions and therefore it is interesting to study the stress responses of plants induced by the single stressors as well as in a in a multi-pollution set-up. The aim of this study was to understand and predict fast induced oxidative stress responses in plants exposed to Cd and U or a combination of both stressors. Arabidopsis thaliana plants grown hydroponically for 18 days were exposed to a Cd (5 μM) or {sup 238}U (25 μM) or an equi-toxic mixture of Cd and {sup 238}U (2.5 μM + 12.5 μM) for 24 h. As expected both metals were taken up into the plants with Cd being more readily transported to the leaves than U. The root-to-shoot ratio was approximately 1,3 for Cd whereas it was above 3500 for U. For both U and Cd the root-to-shoot ratio was not affected under multiple exposure conditions used here. Notwithstanding the limited exposure time, leave and root fresh weight was already decreasing in U-treated plants. For Cd or Cd+U a decreasing but at this point not significant trend was visible. As U concentrations in the leaves were very low the decrease in leaf fresh weight is possibly due to signaling from the roots rather than a direct toxicity of U. The oxidative stress response was investigated by measuring the transcription of selected pro- and anti-oxidative genes, anti-oxidative enzyme capacities and concentration and redox status of major anti-oxidative metabolites. Cd strongly up-regulated lipoxygenase (LOX1) and NADPH-oxidases (RBOHD or C in roots and leaves, respectively) whereas this was not found in the U-treated plants. For the anti-oxidative response related enzymes both Cd and U induced a decrease in Cu/Zn superoxide dismutases (CSD1,2) and a concomitant increase in Fe-SOD (FSD1). However

  3. Chronic waterborne zinc and cadmium exposures induced different responses towards oxidative stress in the liver of zebrafish.

    Science.gov (United States)

    Zheng, Jia-Lang; Yuan, Shuang-Shuang; Wu, Chang-Wen; Li, Wei-Ye

    2016-08-01

    Based on the same toxic level of 0.6% LC50 for 96-h and the severe situation of water pollution, we compared effects of chronic Zn (180μgL(-1)) and Cd exposures (30μgL(-1)) on growth, survival, histology, ultrastructure, and oxidative stress in the liver of zebrafish for 5 weeks. Growth performance and survival rate remained relatively constant under Zn stress, but was reduced under Cd exposure. Cd exposure also induced severe pyknotic nuclei, evident ultrastructure damage, and considerable lipid inclusions in the hepatocytes. However, these phenomena were not pronounced under Zn exposure. The negative effects caused by Cd may be explained by an increase in hepatic oxidative damage, as reflected by the enhanced levels of lipid peroxidation (LPO) and protein carbonylation (PC). The reduced activity of Cu/Zn-superoxide dismutase (Cu/Zn-SOD) and catalase (CAT) may result in the enhanced hepatic oxidative damage, though the mRNA and protein levels of both genes increased and remained unchanged respectively. On the contrary, Zn up-regulated the levels of mRNA, protein and activity of Cu/Zn-SOD, which may contribute to the decreased LPO levels. Nonetheless, the sharply up-regulated mRNA levels of CAT did not induce an increase in the protein and activity levels of CAT under Zn stress. Furthermore, transcription factor NF-E2-related factor 2 (Nrf2) expression parelleled with its target genes, suggesting that Nrf2 is required for the protracted induction of antioxidant genes. In conclusion, our data demonstrated that essential and non-essential metals induced some differences in oxidative damage in fish. The differences were not caused by the transcriptional level of related genes but depended on post-transcriptional modifications. PMID:27323295

  4. Response of Saccharomyces cerevisiae to cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia], e-mail: luamatu@uol.com.br; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Ativacao Neutronica], e-mail: menezes@cdtn.br; Rosa, Carlos Augusto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: carlrosa@icb.ufmg

    2009-07-01

    The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K{sup +} and Na{sup +}) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

  5. Cadmium-induced oxidative stress and histological damage in the myocardium. Effects of a soy-based diet

    International Nuclear Information System (INIS)

    Cd exposure has been associated to an augmented risk for cardiovascular disease. We investigated the effects of 15 and 100 ppm of Cd on redox status as well as histological changes in the rat heart and the putative protective effect of a soy-based diet. Male Wistar rats were separated into 6 groups and treated during 60 days as follows: groups (1), (2) and (3) were fed a casein-based diet; groups (4), (5) and (6), a soy-based diet; (1) and (4) were given tap water; (2) and (5) tap water containing 15 ppm of Cd2+; and (3) and (6) tap water containing 100 ppm of Cd2+. Serum lipid peroxides increased and PON-1 activity decreased in group (3). Lipoperoxidation also increased in the heart of all intoxicated groups; however protein oxidation only augmented in (3) and reduced glutathione levels diminished in (2) and (3). Catalase activity increased in groups (3) and (6) while superoxide dismutase activity increased only in (6). Glutathione peroxidase activity decreased in groups (3) and (6). Nrf2 expression was higher in groups (3) and (6), and MTI expression augmented in (3). Histological examination of the heart tissue showed the development of hypertrophic and fusion of cardiomyocytes along with foci of myocardial fiber necrosis. The transmission electron microscopy analysis showed profound ultra-structural damages. No protection against tissue degeneration was observed in animals fed the soy-based diet. Our findings indicate that even though the intake of a soy-based diet is capable of ameliorating Cd induced oxidative stress, it failed in preventing cardiac damage. -- Highlights: ► Cd intoxication produces extracellular and ultrastructural damage in the myocardium. ► The intake of a soy-based diet ameliorated Cd-induced oxidative stress. ► Cd-induced myocardial damage wasn't prevented by the intake of a soy-based diet. ► Cd-induced myocardial degeneration may not be caused by oxidative stress generation. ► Histology evaluation is needed to establish the

  6. Cadmium-induced oxidative stress and histological damage in the myocardium. Effects of a soy-based diet

    Energy Technology Data Exchange (ETDEWEB)

    Ferramola, Mariana L.; Pérez Díaz, Matías F.F. [Department of Biochemistry and Biological Sciences, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, IMIBIO-SL, CONICET, San Luis (Argentina); Honoré, Stella M.; Sánchez, Sara S. [Department of Development Biology, INSIBIO, National University of Tucumán, CONICET-UNT, Tucumán (Argentina); Antón, Rosa I. [Department of Chemistry, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, INQUISAL, CONICET, San Luis (Argentina); Anzulovich, Ana C. [Department of Biochemistry and Biological Sciences, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, IMIBIO-SL, CONICET, San Luis (Argentina); Giménez, María S., E-mail: mgimenez@unsl.edu.ar [Department of Biochemistry and Biological Sciences, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, IMIBIO-SL, CONICET, San Luis (Argentina)

    2012-12-15

    Cd exposure has been associated to an augmented risk for cardiovascular disease. We investigated the effects of 15 and 100 ppm of Cd on redox status as well as histological changes in the rat heart and the putative protective effect of a soy-based diet. Male Wistar rats were separated into 6 groups and treated during 60 days as follows: groups (1), (2) and (3) were fed a casein-based diet; groups (4), (5) and (6), a soy-based diet; (1) and (4) were given tap water; (2) and (5) tap water containing 15 ppm of Cd{sup 2+}; and (3) and (6) tap water containing 100 ppm of Cd{sup 2+}. Serum lipid peroxides increased and PON-1 activity decreased in group (3). Lipoperoxidation also increased in the heart of all intoxicated groups; however protein oxidation only augmented in (3) and reduced glutathione levels diminished in (2) and (3). Catalase activity increased in groups (3) and (6) while superoxide dismutase activity increased only in (6). Glutathione peroxidase activity decreased in groups (3) and (6). Nrf2 expression was higher in groups (3) and (6), and MTI expression augmented in (3). Histological examination of the heart tissue showed the development of hypertrophic and fusion of cardiomyocytes along with foci of myocardial fiber necrosis. The transmission electron microscopy analysis showed profound ultra-structural damages. No protection against tissue degeneration was observed in animals fed the soy-based diet. Our findings indicate that even though the intake of a soy-based diet is capable of ameliorating Cd induced oxidative stress, it failed in preventing cardiac damage. -- Highlights: ► Cd intoxication produces extracellular and ultrastructural damage in the myocardium. ► The intake of a soy-based diet ameliorated Cd-induced oxidative stress. ► Cd-induced myocardial damage wasn't prevented by the intake of a soy-based diet. ► Cd-induced myocardial degeneration may not be caused by oxidative stress generation. ► Histology evaluation is needed to

  7. The effects of cadmium exposure on the oxidative state and cell death in the gill of freshwater crab Sinopotamon henanense.

    Directory of Open Access Journals (Sweden)

    Jinxiang Wang

    Full Text Available We studied here the short-term toxicity effects of Cd on the oxidative state and cell death in the gill of freshwater crab Sinopotamon henanense. Crabs were exposed to Cd that resulted in Cd accumulation and a significant increase in the metallothionein (MT level in the gill, but MT level increased disproportionally compared to the Cd accumulation with an extension of exposure time. Significant changes in the activities of superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GPx were observed. An increase in the levels of reactive oxygen species (ROS and lipid peroxidation (LPO was detected that will cause oxidative stress. Histological abnormalities of the gills were discovered, including the expansion of gill cavity, a decrease in the numbers of connection of the upper and the lower of the gill lamellae and epithelial cells, and an increase in the number of hemocytes. The results of a TUNEL test and transmission electron microscope (TEM showed that more gill cells had apoptotic characteristics after 48 h of Cd treatment compared to the control, but epithelial cell necrosis and inflammatory response appeared only after 72 h. It was concluded that (1 Cd induced the ROS production and accumulation through inhibiting antioxidant enzyme activities and exceeding the saturation values of MT binging; (2 Cd led to lipid peroxidation and histopathological alternations; and (3 Cd induced apoptotic response at short time exposure, followed by necrotic features and inflammatory reaction after longer time exposure.

  8. Role of salicylic acid in alleviating oxidative damage in rice roots (Oryza sativa) subjected to cadmium stress

    International Nuclear Information System (INIS)

    Time-dependent changes in enzymatic and non-enzymatic antioxidants, and lipid peroxidation were investigated in roots of rice (Oryza sativa) grown hydroponically with Cd, with or without pretreatment of salicylic acid (SA). Exposure to 50 μM Cd significantly decreased root growth, and activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), but increased the concentrations of H2O2, malondialdehyde (MDA), ascorbic acid (AsA), glutathione (GSH) and non-protein thiols (NPT). However, pretreatment with 10 μM SA enhanced the activities of antioxidant enzymes and the concentrations of non-enzymatic antioxidants, but lowered the concentrations of H2O2 and MDA in the Cd-stressed rice compared with the Cd treatment alone. Pretreatment with SA alleviated the Cd-induced inhibition of root growth. The results showed that pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance. The possible mechanism of SA-induced H2O2 signaling in mediating Cd tolerance was discussed. - Pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance

  9. Effect of pristine graphene incorporation on charge storage mechanism of three-dimensional graphene oxide: superior energy and power density retention

    Science.gov (United States)

    Singh, Kiran Pal; Bhattacharjya, Dhrubajyoti; Razmjooei, Fatemeh; Yu, Jong-Sung

    2016-08-01

    In the race of gaining higher energy density, carbon’s capacity to retain power density is generally lost due to defect incorporation and resistance increment in carbon electrode. Herein, a relationship between charge carrier density/charge movement and supercapacitance performance is established. For this purpose we have incorporated the most defect-free pristine graphene into defective/sacrificial graphene oxide. A unique co-solvent-based technique is applied to get a homogeneous suspension of single to bi-layer graphene and graphene oxide. This suspension is then transformed into a 3D composite structure of pristine graphene sheets (GSs) and defective N-doped reduced graphene oxide (N-RGO), which is the first stable and homogenous 3D composite between GS and RGO to the best of our knowledge. It is found that incorporation of pristine graphene can drastically decrease defect density and thus decrease relaxation time due to improved associations between electrons in GS and ions in electrolyte. Furthermore, N doping is implemented selectively only on RGO and such doping is shown to improve the charge carrier density of the composite, which eventually improves the energy density. After all, the novel 3D composite structure of N-RGO and GS greatly improves energy and power density even at high current density (20 A/g).

  10. Incorporation effect of nanosized perovskite LaFe₀.₇Co₀.₃O₃ on the electrochemical activity of Pt nanoparticles-multi walled carbon nanotube composite toward methanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Noroozifar, Meissam, E-mail: mnoroozifar@chem.usb.ac.ir [Department of Chemistry, University of Sistan and Baluchestan, PO Box 98155-147, Zahedan (Iran, Islamic Republic of); Khorasani-Motlagh, Mozhgan; Khaleghian-Moghadam, Roghayeh; Ekrami-Kakhki, Mehri-Saddat; Shahraki, Mohammad [Department of Chemistry, University of Sistan and Baluchestan, PO Box 98155-147, Zahedan (Iran, Islamic Republic of)

    2013-05-01

    Nanosized perovskite LaFe₀.₇Co₀.₃O₃ (LFCO) is synthesized through conventional co-precipitation method and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques. The incorporation effect of the mentioned perovskite to catalytic activity of the PtNPs-MWCNTs-nafion (or -chitosan) catalyst toward methanol oxidation has been studied by cyclic voltammetry. Based on the electrochemical studies, all MWCNTs-PtNPs-nafion (or chitosan) and MWCNTs-PtNPs-LFCO-nafion (or chitosan) catalysts show a considerable activity for methanol oxidation. However, a synergistic effect is observed when LFCO is added to the catalyst by decreasing the poisoning rate of the Pt catalyst. - Graphical abstract: Nanosized perovskite LaFe₀.₇Co₀.₃O₃ is synthesized and characterized. The incorporation effect of the mentioned perovskite to catalytic activity of the PtNPS-MWCNTs-nafion (or -chitosan) catalyst toward methanol oxidation is studied. Highlights: • Nanocrystalline LaFe₀.₇Co₀.₃O₃ (LFCO) is prepared by a new simple co-precipitation method. • Effect of LFCO to catalytic activity of PtNPS for methanol oxidation is studied. • A synergistic effect is observed when LFCO is added to the Pt catalyst. • Oxygen of LFCO could be considered as active oxygen to remove CO intermediates.

  11. Enhanced bone formation in electrospun poly(L-lactic-co-glycolic acid)-tussah silk fibroin ultrafine nanofiber scaffolds incorporated with graphene oxide.

    Science.gov (United States)

    Shao, Weili; He, Jianxin; Sang, Feng; Wang, Qian; Chen, Li; Cui, Shizhong; Ding, Bin

    2016-05-01

    To engineer bone tissue, it is necessary to provide a biocompatible, mechanically robust scaffold. In this study, we fabricated an ultrafine nanofiber scaffold by electrospinning a blend of poly(L-lactic-co-glycolic acid), tussah silk fibroin, and graphene oxide (GO) and characterized its morphology, biocompatibility, mechanical properties, and biological activity. The data indicate that incorporation of 10 wt.% tussah silk and 1 wt.% graphene oxide into poly(L-lactic-co-glycolic acid) nanofibers significantly decreased the fiber diameter from 280 to 130 nm. Furthermore, tussah silk and graphene oxide boosted the Young's modulus and tensile strength by nearly 4-fold and 3-fold, respectively, and significantly enhanced adhesion, proliferation in mouse mesenchymal stem cells and functionally promoted biomineralization-relevant alkaline phosphatase (ALP) and mineral deposition. The results indicate that composite nanofibers could be excellent and versatile scaffolds for bone tissue engineering.

  12. Hepatoprotective activity of Moringa oleifera against cadmium toxicity in rats

    Directory of Open Access Journals (Sweden)

    Reetu Toppo

    2015-04-01

    Full Text Available Aim: The present investigation has been conducted to evaluate the hepatoprotective activity of Moringa oleifera against cadmium-induced toxicity in rats. Materials and Methods: For this study, 18 Wistar albino rats were taken. Control group, Group I rats were given cadmium chloride @ 200 ppm per kg and Group II rats were treated with M. oleifera extract @ 500 mg/kg along with cadmium chloride @ 200 ppm per kg (daily oral for 28 days. On 29th day, animals were slaughtered and various parameters were determined. Serum biomarkers, oxidative stress parameters, histomorphological examination were carried out with estimation of cadmium concentration in liver tissues. Results: Oral administration of cadmium chloride @ 200 ppm/kg for 28 days resulted in a significant increase in aspartate aminotransferase (AST, alanine transaminase (ALT, alkaline phosphatase (ALP, significant (p≤0.01 increase of lipid peroxidation (LPO and decrease in superoxide dismutase (SOD, and increase in cadmium accumulation in liver. Treatment with M. oleifera @ 500 mg/kg significantly (p<0.01 decreased the elevated ALP, AST, ALT, LPO levels and increase in SOD levels, and as compared to cadmium chloride treated group. However, there was no significant difference in cadmium concentration in liver when compared with cadmium chloride treated group. Conclusion: The study conclude that supplementation of M. oleifera (500 mg/kg, daily oral for 28 days has shown protection against cadmium-induced hepatotoxicity.

  13. Transcriptional and biochemical markers in transplanted Perca flavescens to characterize cadmium- and copper-induced oxidative stress in the field

    Energy Technology Data Exchange (ETDEWEB)

    Defo, Michel A. [Institut National De La Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 De La Couronne, Québec, QC G1K 9A9 (Canada); Bernatchez, Louis [Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec, QC G1V 0A6 (Canada); Campbell, Peter G.C.; Couture, Patrice [Institut National De La Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 De La Couronne, Québec, QC G1K 9A9 (Canada)

    2015-05-15

    Highlights: • Four-weeks exposure is sufficient to increase kidney metal levels in wild perch. • Cd and Cu affected indicators of retinoid metabolism and oxidative stress in fish. • Multi-level biological approaches are needed when assessing fish metal toxicology. • Changes at molecular level do not always mean changes at the functional level. • Wild juvenile perch may partly adjust to metal contamination by plastic responses. - Abstract: Despite recent progress achieved in elucidating the mechanisms underlying local adaptation to pollution, little is known about the evolutionary change that may be occurring at the molecular level. The goal of this study was to examine patterns of gene transcription and biochemical responses induced by metal accumulation in clean yellow perch (Perca flavescens) and metal depuration in contaminated fish in a mining and smelting region of Canada. Fish were collected from a reference lake (lake Opasatica) and a Cd, Cu and Zn contaminated lake (lake Dufault) located in the Rouyn-Noranda region (Qc, Canada) and caged for one or four weeks in their own lake or transplanted in the other lake. Free-ranging fish from the same lakes were also collected. Kidney Cd and Cu concentrations in clean fish caged in the contaminated lake increased with the time of exposure, but metal depuration did not occur in contaminated fish caged in the clean lake. After 4 weeks, the major retinoid metabolites analysed, the percentage of free dehydroretinol (dROH) and the retinol dehydrogenase-2 (rdh-2) transcription level in liver decreased in clean fish transplanted into the metal-contaminated lake, suggesting that metal exposure negatively impacted retinoid metabolism. However, we observed an increase in almost all of the retinoid parameters analysed in fish from the metal-impacted lake caged in the same lake, which we interpret as an adaptation response to higher ambient metal concentration. In support of this hypothesis, liver transcription levels

  14. Cadmium-Induced Testicular Toxicity, Oxidative Stress and Histopathology in Wistar Rats: Sustained Effects of Polyphenol-Rich Extract of Vernonia Amygdalina (Del. Leaf

    Directory of Open Access Journals (Sweden)

    Christian Eseigbe Imafidon

    2016-09-01

    Full Text Available Background: Cadmium (Cd is a toxic heavy metal of both environmental and occupational concerns. The health impact of ethno-botanical approaches in attempts to ameliorate its deleterious effects in biological systems should be an area of scientific interest since established therapies are often burdened with undesirable side effects. Aim: To determine the effects of polyphenol-rich extract of the leaf of Vernonia amygdalina (PEVA on Cd-induced testicular toxicity, oxidative stress, and histopathology in Wistar rats. Materials and Methods: A total of twenty five (25 male Wistar rats were divided into five groups as follows: Group 1 (Control received distilled water (0.2 ml/100 g i.p. for 5 consecutive days and thereafter left untreated for 28 days. Group 2 received Cd alone at 5 mg/kg (i.p. for 5 consecutive days. Group 3 was pre-treated with Cd as Group 2 and thereafter left untreated for a period of 28 days, whereas Groups 4 and 5 were pre-treated with Cd as Group 2 and thereafter received PEVA (orally at two dose levels (200 and 400 mg/kg, respectively for 28 days. Results: Cd administration induced reproductive toxicity as evidenced by lowered level of follicle stimulating hormone, luteinizing hormone, and testosterone (P < 0.05; perturbation of sperm characterization (P < 0.05; deleterious disruptions of the antioxidant system as evidenced by lowered levels of reduced glutathione and superoxide dismutase as well as elevation in thiobarbituric acid reactive substances level (P < 0.05; decrease in relative testicular weight (P < 0.05; and severe disseminated necrosis of the seminiferous tubules with terminally undifferentiated/necrotic cells as revealed by the histopathological examination. These conditions were sustained following administration of the two dose levels of PEVA. Conclusion: PEVA administration is not a suitable therapeutic choice for fertility enhancement in male Wistar rat model of Cd-induced decline in reproductive function

  15. FrnE, a cadmium-inducible protein in Deinococcus radiodurans, is characterized as a disulfide isomerase chaperone in vitro and for its role in oxidative stress tolerance in vivo.

    Science.gov (United States)

    Khairnar, Nivedita P; Joe, Min-Ho; Misra, H S; Lim, Sang-Yong; Kim, Dong-Ho

    2013-06-01

    Deinococcus radiodurans R1 exposed to a lethal dose of cadmium shows differential expression of a large number of genes, including frnE (drfrnE) and some of those involved in DNA repair and oxidative stress tolerance. The drfrnE::nptII mutant of D. radiodurans showed growth similar to that of the wild type, but its tolerance to 10 mM cadmium and 10 mM diamide decreased by ~15- and ~3-fold, respectively. These cells also showed nearly 6 times less resistance to gamma radiation at 12 kGy and ~2-fold-higher sensitivity to 40 mM hydrogen peroxide than the wild type. In trans expression of drFrnE increased cytotoxicity of dithiothreitol (DTT) in the dsbA mutant of Escherichia coli. Recombinant drFrnE showed disulfide isomerase activity and could maintain insulin in its reduced form in the presence of DTT. While an equimolar ratio of wild-type protein could protect malate dehydrogenase completely from thermal denaturation at 42 °C, the C22S mutant of drFrnE provided reduced protection to malate dehydrogenase from thermal inactivation. These results suggested that drFrnE is a protein disulfide isomerase in vitro and has a role in oxidative stress tolerance of D. radiodurans possibly by protecting the damaged cellular proteins from inactivation. PMID:23603741

  16. Hepatotoxicity of Cadmium and Roles of Mitigating Agents

    Directory of Open Access Journals (Sweden)

    Elias Adikwu

    2013-12-01

    Full Text Available There are increasing reports on cadmium associated hepatotoxicity, due to these reports this study reviewed relevant literature on cadmium associated hepatotoxicity with emphasis on doses, route of administration, salt forms (cadmium compounds and the roles of mitigating agents. Reports have shown that continuous exposure of the liver to cadmium has led to hepatotoxicity. Humans are generally exposed to cadmium by two main routes, inhalation and ingestion. In this study, evaluation of relevant literature showed that irrespective of route of administration and salt forms cadmium hepatotoxicity is dose and time dependent. Cadmium associated hepatotoxicity manifested through impaired functions of hepatic biomarkers (transaminases, enzymatic and non enzymatic antioxidants. Histopathological damage to liver architecture manifested as swelling of hepatocytes, focal necrosis, hepatocytes degeneration, dilatation of ribosomes, damage of membrane-bounded lysosomes, nuclear pyknosis and cytoplasm vacuolization. Deterioration of mitochondrial cristae, deposition of collagen fibrils, hypertrophy of kuffer cells, congestion in central veins and sinusoids, infiltration of mixed inflammatory cells and peripheral hemorrhage also occurred. Hepatotoxic effect of cadmium was mitigated by Vitamin C, Vitamin E, Manganese (11 Chloride, N-acetylcysteine and Selenium. Extracts of plant origin including Solanum tuberosum, Calycopteris floribunda Hibiscus sabdariffa mitigated cadmium induced hepatotoxicity. Chemical substances of animal origin including honey and camel milk were reported to have ameliorated cadmium induced hepatotoxicity. One of the mechanisms of cadmium induced hepatotoxicity is reported to be associated with the up regulation of reactive oxygen species (oxidative stress which caused oxidative damage to lipid contents of membranes and direct liver injury. Conclusion cadmium is dose and time dependently hepatotoxic irrespective of route of administration

  17. The dynamic changes of the plasma membrane proteins and the protective roles of nitric oxide in rice subjected to heavy metal cadmium stress

    Science.gov (United States)

    The heavy metal cadmium is a common environmental contaminant in soils and has adverse effects on crop growth and development. The signaling processes in plants that initiate cellular responses to environmental stress have been shown to be located in the plasma membrane (PM). A better understanding ...

  18. Effect of nitrogen incorporation into Al-based gate insulators in AlON/AlGaN/GaN metal-oxide-semiconductor structures

    Science.gov (United States)

    Asahara, Ryohei; Nozaki, Mikito; Yamada, Takahiro; Ito, Joyo; Nakazawa, Satoshi; Ishida, Masahiro; Ueda, Tetsuzo; Yoshigoe, Akitaka; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

    2016-10-01

    The superior physical and electrical properties of aluminum oxynitride (AlON) gate dielectrics on AlGaN/GaN substrates in terms of thermal stability, reliability, and interface quality were demonstrated by direct AlON deposition and subsequent annealing. Nitrogen incorporation into alumina was proven to be beneficial both for suppressing intermixing at the insulator/AlGaN interface and reducing the number of electrical defects in Al2O3 films. Consequently, we achieved high-quality AlON/AlGaN/GaN metal-oxide-semiconductor capacitors with improved stability against charge injection and a reduced interface state density as low as 1.2 × 1011 cm-2 eV-1. The impact of nitrogen incorporation into the insulator will be discussed on the basis of experimental findings.

  19. Mechanisms of cadmium carcinogenesis

    International Nuclear Information System (INIS)

    Cadmium (Cd), a heavy metal of considerable occupational and environmental concern, has been classified as a human carcinogen by the International Agency for Research on Cancer (IARC). The carcinogenic potential of Cd as well as the mechanisms underlying carcinogenesis following exposure to Cd has been studied using in vitro cell culture and in vivo animal models. Exposure of cells to Cd results in their transformation. Administration of Cd in animals results in tumors of multiple organs/tissues. Also, a causal relationship has been noticed between exposure to Cd and the incidence of lung cancer in human. It has been demonstrated that Cd induces cancer by multiple mechanisms and the most important among them are aberrant gene expression, inhibition of DNA damage repair, induction of oxidative stress, and inhibition of apoptosis. The available evidence indicates that, perhaps, oxidative stress plays a central role in Cd carcinogenesis because of its involvement in Cd-induced aberrant gene expression, inhibition of DNA damage repair, and apoptosis.

  20. Risk of overestimation of urinary cadmium concentrations: interference from molybdenum

    Directory of Open Access Journals (Sweden)

    Cañas A.I.

    2013-04-01

    Full Text Available We show here that the selection of analytical method is critical when measuring low levels of cadmium in human urine. Cadmium is today usually analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS, which has a higher sensitivity than Atomic Absorption Spectroscopy (AAS. ICP-MS cadmium measurements show interference from tin (114Sn and molybdenum oxides, which can result in an overestimation of cadmium levels. The 114Sn interference is stable and can be mathematically corrected. Molybdenum concentrations in urine are variable and different from individual to individual. We have estimated the degree of error which molybdenum interference introduces in the measurement of cadmium in urine by conventional ICP-MS. 268 urine samples from mothers and their children were measured. Removal of the molybdenum oxide interference (DRC-ICP-MS method reduced urinary cadmium concentrations significantly (47.8%. The urinary molybdenum concentration in children was higher than in their mothers, resulting in greater overestimation. Our results clearly show that the DRC method is essential for reliable measurements of urinary cadmium concentrations, particularly in children. Furthermore, care should be taken when comparing Human Biomonitoring data for cadmium in urine and attention should be paid to which analytical method has been used (e.g. AAS and ICP-Ms, and especially if the measurements have been corrected for molybdenum interference.

  1. An integrated method incorporating sulfur-oxidizing bacteria and electrokinetics to enhance removal of copper from contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Maini, G.; Sharman, A.K.; Sunderland, G.; Knowles, C.J.; Jackman, S.A.

    2000-03-15

    The combination of bioleaching and electrokinetics for the remediation of metal contaminated land has been investigated. In bioleaching, bacteria convert reduced sulfur compounds to sulfuric acid, acidifying soil and mobilizing metal ions. In electrokinetics, DC current acidifies soil, and mobilized metals are transported to the cathode by electromigration. When bioleaching was applied to silt soil artificially contaminated with seven metals and amended with sulfur, bacterial activity was partially inhibited and limited acidification occurred. Electrokinetic treatment of silt soil contaminated solely with 1000 mg/kg copper nitrate showed 89% removal of copper from the soil within 15 days. To combine bioleaching and electrokinetics sequentially, preliminary partial acidification was performed by amending copper-contaminated soil with sulfur (to 5% w/w) and incubating at constant moisture (30% w/w) and temperature (20 C) for 90 days. Indigenous sulfur oxidizing bacteria partially acidified the soil from pH 8.1 to 5.4. This soil was then treated by electrokinetics yielding 86% copper removal in 16 days. In the combined process, electrokinetics stimulated sulfur oxidation, by removing inhibitory factors, yielding a 5.1-fold increase in soil sulfate concentration. Preacidification by sulfur-oxidizing bacteria increased the cost-effectiveness of the electrokinetic treatment by reducing the power requirement by 66%.

  2. Influence of a high level of dietary cadmium on cadmium content in milk, excretion, and cow performance

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.J.; Lampp, B.; Powell, G.W.; Salotti, C.A.; Blackmon, D.M.

    1967-01-01

    Three Holstein cows were each given 3.0 g of cadmium daily (two equal doses) for two weeks by gelatin capsules. There was a sharp drop in concentrate consumption for the first few days of cadmium administration but, by the second week, consumption returned to normal. Milk production declined sharply for several days and then increased appreciably, but to a level still substantially lower than that of controls during the last five days cadmium was given. When cadmium treatments ceased, milk production increased by 50%. Fat content of milk was elevated considerably during the week when production was most reduced. Cows given cadmium lost considerable weight. There were no other clinical manifestations of toxicity. As determined by the chromic oxide indicator method and twice-daily grab samples, fecal excretion of cadmium for the second week averaged 82% of that given. The cadmium level in the urine was below the limits of detectability of the method (0.5 ppm of urine). The cadmium content of the milk was less than 0.1 ppm of the milk, which was the lower reliability limit of the procedure used. On this basis less than 0.22% of the amount administered appeared in the milk. In vitro studies demonstrated that cadmium combines with the casein and whey protein fractions of the milk readily, with the amount combined being linear when levels from 1.0 to 25.0 ppm are added to milk. Smaller amounts were present in the lactose and mineral fractions.

  3. Structural Incorporation of Uranium into Iron Oxides: A Competitive Secondary Sequestration Pathway Mediated by Fe(II)

    Science.gov (United States)

    Massey, M. S.; Lezama-Pacheco, J. S.; Nico, P. S.; Bargar, J.; Fendorf, S.

    2011-12-01

    Uranium retention and sequestration pathways determine the long-term fate of this important contaminant in soils and sediments. Direct, enzymatic U reduction and subsequent precipitation of UO2 is one potential sequestration pathway, but indirect U transformations can also occur as a result of reactions with microbially-generated Fe(II). Here we explored uranium retention mechanisms active during abiotic reduction of U(VI) by aqueous Fe(II), in the presence of ferrihydrite, in Ca and carbonate-bearing solutions. Ferrihydrite transformation and U reduction were studied in batch incubations containing Ca (0 and 4 mM), carbonate (3.8 mM), ferrihydrite (~180 mg/L), Fe(II) (0.3 mM), and a range of concentrations of uranyl (1 to 170 μM). Uranium retention pathways were differentiated using extended x-ray absorption fine structure (EXAFS) spectroscopy and synchrotron X-ray powder diffraction. At U concentrations >50 μM, U(VI) reduction to U(IV) and subsequent precipitation of UO2 was a dominant sequestration pathway. At lower U concentrations (1-10 μM), UO2 precipitation was not observed and incorporation into goethite, the secondary transformation product of ferrihydrite, was dominant. For groundwaters having micromolar U(VI) concentrations, U incorporation into ferrihydrite transformation products via microbially-produced Fe(II) may be an important sequestration process.

  4. SaOS-2 cell response to macro-porous boron-incorporated TiO2 coating prepared by micro-arc oxidation on titanium.

    Science.gov (United States)

    Huang, Qianli; Elkhooly, Tarek A; Liu, Xujie; Zhang, Ranran; Yang, Xing; Shen, Zhijian; Feng, Qingling

    2016-10-01

    The aims of the present study were to develop boron-incorporated TiO2 coating (B-TiO2 coating) through micro-arc oxidation (MAO) and subsequently evaluate the effect of boron incorporation on the in vitro biological performance of the coatings. The physicochemical properties of B-TiO2 coating and its response to osteoblast like cells (SaOS-2) were investigated compared to the control group without boron (TiO2 coating). The morphological and X-ray diffraction results showed that both coatings exhibited similar surface topography and phase composition, respectively. However, the incorporation of B led to an enhancement in the surface hydrophilicity of B-TiO2 coating. The spreading of SaOS-2 cells on B-TiO2 coating was faster than that on TiO2 coating. The proliferation rate of SaOS-2 cells cultured on B-TiO2 decreased after 5days of culture compared to that on TiO2 coating. SaOS-2 cells cultured on B-TiO2 coating exhibited an enhanced alkaline phosphatase (ALP) activity, Collagen I synthesis and in vitro mineralization compared to those on TiO2 coating. The present findings suggest that B-TiO2 coating is a promising candidate surface for orthopedic implants.

  5. SaOS-2 cell response to macro-porous boron-incorporated TiO2 coating prepared by micro-arc oxidation on titanium.

    Science.gov (United States)

    Huang, Qianli; Elkhooly, Tarek A; Liu, Xujie; Zhang, Ranran; Yang, Xing; Shen, Zhijian; Feng, Qingling

    2016-10-01

    The aims of the present study were to develop boron-incorporated TiO2 coating (B-TiO2 coating) through micro-arc oxidation (MAO) and subsequently evaluate the effect of boron incorporation on the in vitro biological performance of the coatings. The physicochemical properties of B-TiO2 coating and its response to osteoblast like cells (SaOS-2) were investigated compared to the control group without boron (TiO2 coating). The morphological and X-ray diffraction results showed that both coatings exhibited similar surface topography and phase composition, respectively. However, the incorporation of B led to an enhancement in the surface hydrophilicity of B-TiO2 coating. The spreading of SaOS-2 cells on B-TiO2 coating was faster than that on TiO2 coating. The proliferation rate of SaOS-2 cells cultured on B-TiO2 decreased after 5days of culture compared to that on TiO2 coating. SaOS-2 cells cultured on B-TiO2 coating exhibited an enhanced alkaline phosphatase (ALP) activity, Collagen I synthesis and in vitro mineralization compared to those on TiO2 coating. The present findings suggest that B-TiO2 coating is a promising candidate surface for orthopedic implants. PMID:27287114

  6. Solvent-Assisted Oxygen Incorporation of Vertically Aligned MoS2 Ultrathin Nanosheets Decorated on Reduced Graphene Oxide for Improved Electrocatalytic Hydrogen Evolution.

    Science.gov (United States)

    Liu, Aiping; Zhao, Li; Zhang, Junma; Lin, Liangxu; Wu, Huaping

    2016-09-28

    Three-dimensional oxygen-incorporated MoS2 ultrathin nanosheets decorated on reduced graphene oxide (O-MoS2/rGO) had been successfully fabricated through a facile solvent-assisted hydrothermal method. The origin of the incorporated oxygen and its incorporation mechanism into MoS2 were carefully investigated. We found that the solvent N,N-dimethylformamide (DMF) was the key as the reducing agent and the oxygen donor, expanding interlayer spaces and improving intrinsic conductivity of MoS2 sheets (modulating its electronic structure and vertical edge sites). These O dopants, vertically aligned edges and decoration with rGO gave effectively improved double-layer capacitance and catalytic performance for hydrogen evolution reaction (HER) of MoS2. The prepared O-MoS2/rGO catalysts showed an exceptional small Tafel slope of 40 mV/decade, a high current density of 20 mA/cm(2) at the overpotential of 200 mV and remarkable stability even after 2000th continuous HER test in the acid media.

  7. Cadmium toxicity and treatment.

    Science.gov (United States)

    Bernhoft, Robin A

    2013-01-01

    Cadmium is a heavy metal of considerable toxicity with destructive impact on most organ systems. It is widely distributed in humans, the chief sources of contamination being cigarette smoke, welding, and contaminated food and beverages. Toxic impacts are discussed and appear to be proportional to body burden of cadmium. Detoxification of cadmium with EDTA and other chelators is possible and has been shown to be therapeutically beneficial in humans and animals when done using established protocols.

  8. Cadmium Toxicity and Treatment

    Directory of Open Access Journals (Sweden)

    Robin A. Bernhoft

    2013-01-01

    Full Text Available Cadmium is a heavy metal of considerable toxicity with destructive impact on most organ systems. It is widely distributed in humans, the chief sources of contamination being cigarette smoke, welding, and contaminated food and beverages. Toxic impacts are discussed and appear to be proportional to body burden of cadmium. Detoxification of cadmium with EDTA and other chelators is possible and has been shown to be therapeutically beneficial in humans and animals when done using established protocols.

  9. Cadmium Toxicity and Treatment

    OpenAIRE

    Bernhoft, Robin A.

    2013-01-01

    Cadmium is a heavy metal of considerable toxicity with destructive impact on most organ systems. It is widely distributed in humans, the chief sources of contamination being cigarette smoke, welding, and contaminated food and beverages. Toxic impacts are discussed and appear to be proportional to body burden of cadmium. Detoxification of cadmium with EDTA and other chelators is possible and has been shown to be therapeutically beneficial in humans and animals when done using established proto...

  10. A transparent conductive oxide electrode with highly enhanced flexibility achieved by controlled crystallinity by incorporating Ag nanoparticles on substrates

    International Nuclear Information System (INIS)

    Highlights: • We developed a composite transparent electrode with Ag nanoparticles and indium-tin-oxide. • Transmittance of AgNPs was improved by formation of oxide layers by O2 plasma treatment. • Ag nanoparticles became crystalline seeds to grow strong ITO with a uniform growth orientation. • The hybrid electrode is highly more conductive and stable under bending than ITO. - Abstract: We report the synthesis of highly flexible indium tin oxide (ITO) on a polymer substrate whose surface was engineered by oxide-coated Ag nanoparticles (AgNPs) smaller than 20 nm in diameter. Polyimide (PI) substrates were spin coated with Ag ion ink and were subsequently heat treated to form AgNP coatings. The Ag oxide was formed by O2 plasma treatment to reduce the light absorbance by AgNPs. ITO was dc magnetron sputter-deposited atop the AgNPs. The ITO on the AgNPs was crystalline grown primarily with (2 2 2) growth orientation. This contrasts to the typical microstructure of ITO grown on the polymer, which is that growing c-ITO nucleates are embedded in an amorphous ITO (a-ITO) matrix like a particulate composite. The surface roughness of ITO on AgNPs was as small as the ITO on PI without AgNPs. The crystalline nature of the ITO on the AgNP-coated polymer resulted in the decrease of electric resistivity (ρ) by 65% compared to that of ITO on the bare PI. Furthermore, an electric resistivity change (Δρ) of the ITO on the AgNPs was only 8% at a bending radius (rb) down to 4 mm, whereas the ITO on the non-coated polymer became almost insulating at an rb of 10 mm, owing to a drastic increase in the number of cracks. To validate the potential application in the displays, flexible organic light emitting diodes (f-OLEDs) were fabricated on the ITO on AgNPs and the performances was compared with the f-OLED on ITO on the bare PI

  11. The fatty acid profile of rainbow trout liver cells modulates their tolerance to methylmercury and cadmium.

    Science.gov (United States)

    Ferain, Aline; Bonnineau, Chloé; Neefs, Ineke; Rees, Jean François; Larondelle, Yvan; Schamphelaere, Karel A C De; Debier, Cathy

    2016-08-01

    The polyunsaturated fatty acid (PUFA) composition of fish tissues, which generally reflects that of the diet, affects various cellular properties such as membrane structure and fluidity, energy metabolism and susceptibility to oxidative stress. Since these cellular parameters can play an important role in the cellular response to organic and inorganic pollutants, a variation of the PUFA supply might modify the toxicity induced by such xenobiotics. In this work, we investigated whether the cellular fatty acid profile has an impact on the in vitro cell sensitivity to two environmental pollutants: methylmercury and cadmium. Firstly, the fatty acid composition of the rainbow trout liver cell line RTL-W1 was modified by enriching the growth medium with either alpha-linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), linoleic acid (LA, 18:2n-6), arachidonic acid (AA, 20:4n-6) or docosapentaenoic acid (DPA, 22:5n-6). These modified cells and their control (no PUFA enrichment) were then challenged for 24h with increasing concentrations of methylmercury or cadmium. We observed that (i) the phospholipid composition of the RTL-W1 cells was profoundly modulated by changing the PUFA content of the growth medium: major modifications were a high incorporation of the supplemented PUFA in the cellular phospholipids, the appearance of direct elongation and desaturation metabolites in the cellular phospholipids as well as a change in the gross phospholipid composition (PUFA and monounsaturated fatty acid (MUFA) levels and n-3/n-6 ratio); (ii) ALA, EPA and DPA enrichment significantly protected the RTL-W1 cells against both methylmercury and cadmium; (iv) DHA enrichment significantly protected the cells against cadmium but not methylmercury; (v) AA and LA enrichment had no impact on the cell tolerance to both methylmercury and cadmium; (vi) the abundance of 20:3n-6, a metabolite of the n-6 biotransformation pathway, in

  12. Different arsenate and phosphate incorporation effects on the nucleation and growth of iron(III) (Hydr)oxides on quartz.

    Science.gov (United States)

    Neil, Chelsea W; Lee, Byeongdu; Jun, Young-Shin

    2014-10-21

    Iron(III) (hydr)oxides play an important role in the geochemical cycling of contaminants in natural and engineered aquatic systems. The ability of iron(III) (hydr)oxides to immobilize contaminants can be related to whether the precipitates form heterogeneously (e.g., at mineral surfaces) or homogeneously in solution. Utilizing grazing incidence small-angle X-ray scattering (GISAXS), we studied heterogeneous iron(III) (hydr)oxide nucleation and growth on quartz substrates for systems containing arsenate and phosphate anions. For the iron(III) only system, the radius of gyration (Rg) of heterogeneously formed precipitates grew from 1.5 to 2.5 (± 1.0) nm within 1 h. For the system containing 10(-5) M arsenate, Rg grew from 3.6 to 6.1 (± 0.5) nm, and for the system containing 10(-5) M phosphate, Rg grew from 2.0 to 4.0 (± 0.2) nm. While the systems containing these oxyanions had more growth, the system containing only iron(III) had the most nucleation events on substrates. Ex situ analyses of homogeneously and heterogeneously formed precipitates indicated that precipitates in the arsenate system had the highest water content and that oxyanions may bridge iron(III) hydroxide polymeric embryos to form a structure similar to ferric arsenate or ferric phosphate. These new findings are important because differences in nucleation and growth rates and particle sizes will impact the number of available reactive sites and the reactivity of newly formed particles toward aqueous contaminants.

  13. Gadolinium chloride pretreatment ameliorates acute cadmium-induced hepatotoxicity.

    Science.gov (United States)

    Kyriakou, Loukas G; Tzirogiannis, Konstantinos N; Demonakou, Maria D; Kourentzi, Kalliopi T; Mykoniatis, Michael G; Panoutsopoulos, Georgios I

    2013-08-01

    Cadmium is a known industrial and environmental pollutant. It causes hepatotoxicity upon acute administration. Features of cadmium-induced acute hepatoxicity encompass necrosis, apoptosis, peliosis and inflammatory infiltration. Gadolinium chloride (GdCl3) may prevent cadmium-induced hepatotoxicity by suppressing Kupffer cells. The effect of GdCl3 pretreatment on a model of acute cadmium-induced liver injury was investigated. Male Wistar rats 4-5 months old were injected intraperitoneally with normal saline followed by cadmium chloride (CdCl2; 6.5 mg/kg) or GdCl3 (10 mg/kg) followed by CdCl2 (6.5 mg/kg; groups I and II, respectively). Rats of both the groups were killed at 9, 12, 16, 24, 48 and 60 h after cadmium intoxication. Liver sections were analyzed for necrosis, apoptosis, peliosis and mitoses. Liver regeneration was also evaluated by tritiated thymidine incorporation into hepatic DNA. Serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also determined. Hepatic necrosis, hepatocyte and nonparenchymal cell apoptosis and macroscopic and microscopic types of peliosis hepatis were minimized by gadolinium pretreatment. Serum levels of AST and ALT were also greatly diminished in rats of group II. Tritiated thymidine incorporation into hepatic DNA was increased in gadolinium pretreatment rats. Kupffer cell activation was minimal in both the groups of rats. Gadolinium pretreatment attenuates acute cadmium-induced liver injury in young Wistar rats, with mechanisms other than Kupffer cell elimination.

  14. Improved electrical properties of silicon-incorporated anodic niobium oxide formed on porous Nb-Si substrate

    International Nuclear Information System (INIS)

    In the present study, porous Nb-Si alloy films with isolated nano-column morphology have been successfully developed by oblique angle magnetron sputtering on to aluminum substrate with concave cell structure. The deposited films are amorphous with the 15 at% silicon supersaturated into niobium. The porous Nb-15 at% Si films, as well as niobium films with similar morphology, are anodized at several voltages up to 50 V in 0.1 mol dm-3 ammonium pentaborate electrolyte. Due to the presence of sufficient gaps between neighboring columns, the gaps are not filled with anodic oxide, despite the large Pilling-Bedworth ratio (for instance, 2.6 for Nb/Nb2O5) and hence, a linear correlation between the reciprocal of capacitance and formation voltage is obtained for the Nb-15 at% Si. From the comparison with the anodic films formed on porous niobium films, it has been found that silicon addition improves the thermal stability of anodic niobium oxide; the change in capacitance and increase in leakage current become small for the Nb-Si. The findings indicate the potential of oblique angle deposition to tailor porous non-equilibrium niobium alloy films for high performance niobium-base capacitor.

  15. Reduction of the interfacial trap density of indium-oxide thin film transistors by incorporation of hafnium and annealing process

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Meng-Fang, E-mail: LIN.MengFang@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Gao, Xu; Mitoma, Nobuhiko; Kizu, Takio; Ou-Yang, Wei; Tsukagoshi, Kazuhito, E-mail: LIN.MengFang@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Aikawa, Shinya [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Research Institute for Science and Technology, Kogakuin University, Hachioji, Tokyo 192-0015 (Japan); Nabatame, Toshihide [MANA Foundry and MANA Advanced Device Materials Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2015-01-15

    The stable operation of transistors under a positive bias stress (PBS) is achieved using Hf incorporated into InO{sub x}-based thin films processed at relatively low temperatures (150 to 250 °C). The mobilities of the Hf-InO{sub x} thin-film transistors (TFTs) are higher than 8 cm{sup 2}/Vs. The TFTs not only have negligible degradation in the mobility and a small shift in the threshold voltage under PBS for 60 h, but they are also thermally stable at 85 °C in air, without the need for a passivation layer. The Hf-InO{sub x} TFT can be stable even annealed at 150 °C for positive bias temperature stability (PBTS). A higher stability is achieved by annealing the TFTs at 250 °C, originating from a reduction in the trap density at the Hf-InO{sub x}/gate insulator interface. The knowledge obtained here will aid in the realization of stable TFTs processed at low temperatures.

  16. Reduction of the interfacial trap density of indium-oxide thin film transistors by incorporation of hafnium and annealing process

    International Nuclear Information System (INIS)

    The stable operation of transistors under a positive bias stress (PBS) is achieved using Hf incorporated into InOx-based thin films processed at relatively low temperatures (150 to 250 °C). The mobilities of the Hf-InOx thin-film transistors (TFTs) are higher than 8 cm2/Vs. The TFTs not only have negligible degradation in the mobility and a small shift in the threshold voltage under PBS for 60 h, but they are also thermally stable at 85 °C in air, without the need for a passivation layer. The Hf-InOx TFT can be stable even annealed at 150 °C for positive bias temperature stability (PBTS). A higher stability is achieved by annealing the TFTs at 250 °C, originating from a reduction in the trap density at the Hf-InOx/gate insulator interface. The knowledge obtained here will aid in the realization of stable TFTs processed at low temperatures

  17. Characterisation of a re-cast composite Nafion 1100 series of proton exchange membranes incorporating inert inorganic oxide particles

    International Nuclear Information System (INIS)

    A series of cation exchange membranes was produced by impregnating and coating both sides of a quartz web with a Nafion solution (1100 EW, 10%wt in water). Inert filler particles (SiO2, ZrO2 or TiO2; 5-20%wt) were incorporated into the aqueous Nafion solution to produce robust, composite membranes. Ion-exchange capacity/equivalent weight, water take-up, thickness change on hydration and ionic and electrical conductivity were measured in 1 mol dm-3 sulfuric acid at 298 K. The TiO2 filler significantly impacted on these properties, producing higher water take-up and increased conductivity. Such membranes may be beneficial for proton exchange membrane (PEM) fuel cell operation at low humidification. The PEM fuel cell performance of the composite membranes containing SiO2 fillers was examined in a Ballard Mark 5E unit cell. While the use of composite membranes offers a cost reduction, the unit cell performance was reduced, in practice, due to drying of the ionomer at the cathode.

  18. Reduction of the interfacial trap density of indium-oxide thin film transistors by incorporation of hafnium and annealing process

    Directory of Open Access Journals (Sweden)

    Meng-Fang Lin

    2015-01-01

    Full Text Available The stable operation of transistors under a positive bias stress (PBS is achieved using Hf incorporated into InOx-based thin films processed at relatively low temperatures (150 to 250 °C. The mobilities of the Hf-InOx thin-film transistors (TFTs are higher than 8 cm2/Vs. The TFTs not only have negligible degradation in the mobility and a small shift in the threshold voltage under PBS for 60 h, but they are also thermally stable at 85 °C in air, without the need for a passivation layer. The Hf-InOx TFT can be stable even annealed at 150 °C for positive bias temperature stability (PBTS. A higher stability is achieved by annealing the TFTs at 250 °C, originating from a reduction in the trap density at the Hf-InOx/gate insulator interface. The knowledge obtained here will aid in the realization of stable TFTs processed at low temperatures.

  19. Characterisation of a re-cast composite Nafion 1100 series of proton exchange membranes incorporating inert inorganic oxide particles

    Energy Technology Data Exchange (ETDEWEB)

    Slade, S.M.; Smith, J.R.; Campbell, S.A. [School of Pharmacy and Biomedical Sciences, University of Portsmouth, St. Michael' s Building, White Swan Road, Portsmouth PO1 2DT (United Kingdom); Ralph, T.R. [Johnson Matthey Fuel Cells, Lydiard Fields, Great Western Way, Swindon SN5 8AT (United Kingdom)] [Electrochemical Engineering Laboratory, Energy Technology Research Group, School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Ponce de Leon, C. [Electrochemical Engineering Laboratory, Energy Technology Research Group, School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Walsh, F.C., E-mail: F.C.Walsh@soton.ac.u [Electrochemical Engineering Laboratory, Energy Technology Research Group, School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)

    2010-09-01

    A series of cation exchange membranes was produced by impregnating and coating both sides of a quartz web with a Nafion solution (1100 EW, 10%wt in water). Inert filler particles (SiO{sub 2}, ZrO{sub 2} or TiO{sub 2}; 5-20%wt) were incorporated into the aqueous Nafion solution to produce robust, composite membranes. Ion-exchange capacity/equivalent weight, water take-up, thickness change on hydration and ionic and electrical conductivity were measured in 1 mol dm{sup -3} sulfuric acid at 298 K. The TiO{sub 2} filler significantly impacted on these properties, producing higher water take-up and increased conductivity. Such membranes may be beneficial for proton exchange membrane (PEM) fuel cell operation at low humidification. The PEM fuel cell performance of the composite membranes containing SiO{sub 2} fillers was examined in a Ballard Mark 5E unit cell. While the use of composite membranes offers a cost reduction, the unit cell performance was reduced, in practice, due to drying of the ionomer at the cathode.

  20. Enhanced performance of polyimide hybrid membranes for benzene separation by incorporating three-dimensional silver-graphene oxide.

    Science.gov (United States)

    Dai, Shi-Qi; Jiang, Yang-Yang; Wang, Ting; Wu, Li-Guang; Yu, Xin-Yi; Lin, Jun-Ze; Shi, Shen-Xuan-Xiang

    2016-09-15

    Graphene oxide-Ag nanoparticle composites were prepared through impregnation reduction using different reactants. Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy analyses were performed to characterize differences in the morphologies of three different Ag-GO composites. Scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry analyses were also applied to evaluate the morphology and thermal stability of the hybrid membranes. Swelling-sorption and pervaporation experiments of benzene and cyclohexane were conducted to evaluate the separation performance of hybrid membranes containing different Ag-GO composites. Results demonstrated that small Ag nanoparticles generated through impregnation reduction using Ag(NH3)2(+) and PEG were homogeneously distributed in the hybrid membranes because of moderate reduction rate. The polymide (PI) hybrid membrane exhibited high separation performance. Increase in Ag content in the Ag-GO samples led to the formation of Ag particles on the GO surface; these particles enhanced the separation performance of the hybrid membranes. When Ag-GO samples with 15 mass percent added, the hybrid membrane showed the highest separation performance and its maximum separation factor in the pervaporation experiments reached 35. It is more than three times higher than that of the GO/PI hybrid membrane. Moreover, large Ag particles were formed and aggregated during the preparation and polymerization of Ag-GO samples with high Ag contents; these particles reduced the separation performance of the hybrid membranes. PMID:27295318

  1. Thin Film Transistor Gas Sensors Incorporating High-Mobility Diketopyrrolopyrole-Based Polymeric Semiconductor Doped with Graphene Oxide.

    Science.gov (United States)

    Cheon, Kwang Hee; Cho, Jangwhan; Kim, Yun-Hi; Chung, Dae Sung

    2015-07-01

    In this work, we fabricated a diketopyrrolopyrole-based donor-acceptor copolymer composite film. This is a high-mobility semiconductor component with a functionalized-graphene-oxide (GO) gas-adsorbing dopant, used as an active layer in gas-sensing organic-field-effect transistor (OFET) devices. The GO content of the composite film was carefully controlled so that the crystalline orientation of the semiconducting polymer could be conserved, without compromising its gas-adsorbing ability. The resulting optimized device exhibited high mobility (>1 cm(2) V(-1) s(-1)) and revealed sensitive response during programmed exposure to various polar organic molecules (i.e., ethanol, acetone, and acetonitrile). This can be attributed to the high mobility of polymeric semiconductors, and also to their high surface-to-volume ratio of GO. The operating mechanism of the gas sensing GO-OFET is fully discussed in conjunction with charge-carrier trap theory. It was found that each transistor parameter (e.g., mobility, threshold voltage), responds independently to each gas molecule, which enables high selectivity of GO-OFETs for various gases. Furthermore, we also demonstrated practical GO-OFET devices that operated at low voltage (gas exposure. PMID:26068504

  2. Effects of bacteria on cadmium bioaccumulation in the cadmium hyperaccumulator plant Beta vulgaris var. cicla L.

    Science.gov (United States)

    Chen, Su; Chao, Lei; Sun, Lina; Sun, Tieheng

    2013-01-01

    To investigate the effects of two cadmium-tolerant bacteria, Staphylococcus pasteuri (S. pasteuri X1) and Agrobacterium tumefaciens (A. tumefaciens X2), on cadmium uptake by the cadmium hyperaccumulator plant Beta vulgaris var. cicla L., a pot experiment with artificially contaminated soil was conducted. The results demonstrated that both cadmium-tolerant bacteria enhanced the dry weight of Beta vulgaris var. cicla L. The total dry weights of plants in the control CK20, S. pasteuri X1 and A. tumefaciens X2 treatments were 0.85, 1.13, and 1.38 g/pot, respectively. Compared with the control CK20 findings, the total dry weight of plants was increased by 32.8 and 61.1% after inoculation with S. pasteuri X1 and A. tumefaciens X2, respectively, indicating that A. tumefaciens X2 more strongly promoted the growth of Beta vulgaris var. cicla L. than S. pasteuri X1. In addition, inoculation with S. pasteuri X1 and A. tumefaciens X2 significantly (p < 0.05) promoted cadmium uptake by plants and improved the bioaccumulation of cadmium by the plants from the soil. Moreover, the inoculation of S. pasteuri X1 and A. tumefaciens X2 effectively facilitated the transfer of cadmium in the soil from the Fe-Mn oxide and residual fractions to the soluble plus exchangeable and weakly specially adsorbed fractions in the rhizosphere soils of plants. The bacterial enhancement of cadmium phytoavailability might provide a potential and promising method to increase the efficiency of phytoextraction. PMID:23488173

  3. A new solid polymer electrolyte incorporating Li10GeP2S12 into a polyethylene oxide matrix for all-solid-state lithium batteries

    Science.gov (United States)

    Zhao, Yanran; Wu, Chuan; Peng, Gang; Chen, Xiaotian; Yao, Xiayin; Bai, Ying; Wu, Feng; Chen, Shaojie; Xu, Xiaoxiong

    2016-01-01

    Li10GeP2S12 (LGPS) is incorporated into polyethylene oxide (PEO) matrix to fabricate composite solid polymer electrolyte (SPE) membranes. The lithium ion conductivities of as-prepared composite membranes are evaluated, and the optimal composite membrane exhibits a maximum ionic conductivity of 1.21 × 10-3 S cm-1 at 80 °C and an electrochemical window of 0-5.7 V. The phase transition behaviors for electrolytes are characterized by DSC, and the possible reasons for their enhanced ionic conductivities are discussed. The LGPS microparticles, acting as active fillers incorporation into the PEO matrix, have a positive effect on the ionic conductivity, lithium ion transference number and electrochemical stabilities. In addition, two kinds of all-solid-state lithium batteries (LiFeO4/SPE/Li and LiCoO2/SPE/Li) are fabricated to demonstrate the good compatibility between this new SPE membrane and different electrodes. And the LiFePO4/Li battery exhibits fascinating electrochemical performance with high capacity retention (92.5% after 50 cycles at 60 °C) and attractive capacities of 158, 148, 138 and 99 mAh g-1 at current rates of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C, respectively. It is demonstrated that this new composite SPE should be a promising electrolyte applied in solid state batteries based on lithium metal electrode.

  4. Temperature-dependent effects of cadmium and purine nucleotides on mitochondrial aconitase from a marine ectotherm, Crassostrea virginica: a role of temperature in oxidative stress and allosteric enzyme regulation.

    Science.gov (United States)

    Cherkasov, Anton A; Overton, Robert A; Sokolov, Eugene P; Sokolova, Inna M

    2007-01-01

    Temperature and heavy metals such as cadmium (Cd) are important environmental stressors that can strongly affect mitochondrial function of marine poikilotherms. In this study, we investigated the combined effects of temperature (20 degrees C and 30 degrees C) and Cd stress on production of reactive oxygen species (ROS) and oxidative stress in a marine poikilotherm Crassostrea virginica (the eastern oyster) using mitochondrial aconitase as a sensitive biomarker of oxidative damage. We also assessed potential involvement of mitochondrial uncoupling proteins (UCPs) in antioxidant protection in oyster mitochondria using purine nucleotides (GDP, ATP and ADP) as specific inhibitors, and free fatty acids as stimulators, of UCPs. Our results show that exposure to Cd results in elevated ROS production and oxidative damage as indicated by aconitase inactivation which is particularly pronounced at elevated temperature. Unexpectedly, oyster mitochondrial aconitase was inhibited by physiologically relevant levels of ATP (IC(50)=1.93 and 3.04 mmol l(-1) at 20 degrees C and 30 degrees C, respectively), suggesting that allosteric regulation of aconitase by this nucleotide may be involved in regulation of the tricarboxylic acid flux in oysters. Aconitase was less sensitive to ATP inhibition at 30 degrees C than at 20 degrees C, consistent with the elevated metabolic flux at higher temperatures. ADP and GDP also inhibited mitochondrial aconitase but at the levels well above the physiological concentrations of these nucleotides (6-11 mmol l(-1)). Our study shows expression of at least three UCP isoforms in C. virginica gill tissues but provides no indication that UCPs protect mitochondrial aconitase from oxidative inactivation in oysters. Overall, the results of this study indicate that temperature stress exaggerates toxicity of Cd leading to elevated oxidative stress in mitochondria, which may have important implications for survival of poikilotherms in polluted environments during

  5. Cation exchange for mercury and cadmium of xanthated, sulfonated, activated and non-treated subbituminous coal, commercial activated carbon and commercial synthetic resin:effect of pre-oxidation on xanthation of subbituminous coal

    Institute of Scientific and Technical Information of China (English)

    Lewis M. Gomez; Fredy Colpas-Castillo; Roberto Fernandez-Maestre

    2014-01-01

    A subbituminous coal was oxidized with air at 150 ?C on a fixed bed for 4 h and xanthated with carbon disulfide in a basic solution, at 30 or 5–10 ?C. This xanthated coal was evaluated for the removal of Hg2? and Cd2? from 7,000 mg/L aqueous solutions; metal concentrations were determined by atomic absorption spectrometry. The ion exchange of the xanthated coal was compared against those of the original subbituminous coal, a sulfonated subbituminous coal, activated carbon, commercial activated carbon, and commercial synthetic resin. The commercial synthetic resin showed the highest exchange capacity (concentration factor 98%) followed by the xanthated coal (concentration factor 96%). The retention of cadmium on the sulfonated subbituminous coal was lower (exchange capacity 0.56 meq/g) than that of xanthated coals (1.85 ± 0.09 meq/g). Our xanthated coal showed a better Cd2? removal (81%against 15%) than a non preoxidized 40-h-xanthated coal, which shows that oxidation of coal increased the amount of oxygenated groups which enhanced xanthation.

  6. Cadmium status in Egypt

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is inferred from these studies that releases of Cd are still increasing and it is recommended that measures must be taken to reduce emissions of cadmium. Any cadmium discharged into the Egyptian environment may move from one compartment to another at varying rates,resulting in an accumulation in compartments such as soils and biota. Such accumulation can be expected to increase with continued emissions,and attention should be given to all sources of cadmium, natural as well as anthropogenic especially in the industrial cities in Egypt. Cadmium present in sewage, as well as industrial effluent (also, other liquid and solid wastes) and sewage sludge will increase levels in soils and is xpected to contribute to dietary levels and body burdens. The current information indicates that such effects may have to be evaluated over long periods of time, possibly as long as 50 - 100 years.

  7. Mitigation of methane and nitrous oxide emissions from flood-irrigated rice by no incorporation of winter crop residues into the soil

    Directory of Open Access Journals (Sweden)

    Tiago Zschornack

    2011-04-01

    Full Text Available Winter cover crops are sources of C and N in flooded rice production systems, but very little is known about the effect of crop residue management and quality on soil methane (CH4 and nitrous oxide (N2O emissions. This study was conducted in pots in a greenhouse to evaluate the influence of crop residue management (incorporated into the soil or left on the soil surface and the type of cover-crop residues (ryegrass and serradella on CH4 and N2O emissions from a flooded Albaqualf soil cultivated with rice (Oryza sativa L.. The closed chamber technique was used for air sampling and the CH4 and N2O concentrations were analyzed by gas chromatography. Soil solution was sampled at two soil depths (2 and 20 cm, simultaneously to air sampling, and the contents of dissolved organic C (DOC, NO3-, NH4+, Mn2+, and Fe2+ were analyzed. Methane and N2O emissions from the soil where crop residues had been left on the surface were lower than from soil with incorporated residues. The type of crop residue had no effect on the CH4 emissions, while higher N2O emissions were observed from serradella (leguminous than from ryegrass, but only when the residues were left on the soil surface. The more intense soil reduction verified in the deeper soil layer (20 cm, as evidenced by higher contents of reduced metal species (Mn2+ and Fe2+, and the close relationship between CH4 emission and the DOC contents in the deeper layer indicated that the sub-surface layer was the main CH4 source of the flooded soil with incorporated crop residues. The adoption of management strategies in which crop residues are left on the soil surface is crucial to minimize soil CH4 and N2O emissions from irrigated rice fields. In these production systems, CH4 accounts for more than 90 % of the partial global warming potential (CH4+N2O and, thus, should be the main focus of research.

  8. Facile one-pot synthesis of nickel-incorporated titanium dioxide/graphene oxide composites: Enhancement of photodegradation under visible-irradiation

    Science.gov (United States)

    Pham, Thanh-Truc; Nguyen-Huy, Chinh; Shin, Eun Woo

    2016-07-01

    Nickel (Ni)-incorporated titanium dioxide (TiO2)/graphene oxide composite photocatalysts were prepared by anchoring the TiO2 and Ni onto the surface of graphene oxide (GO) sheets by a straightforward microwave-assisted, one-pot method for the first time. The as-prepared composite photocatalysts with high Ni content (40-50 wt%) showed good adsorption capacity in the dark and high reaction rate constants under visible illumination while the composite photocatalysts with low Ni content (5-10 wt%) exhibited weak activity. An anatase phase, a small amount of rutile phase and Ni metal were detected using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Raman measurements identified a small fraction of NiTiO3 only at high Ni content. The formation of NiTiO3 and the increase in the specific surface area (SSA) for 40 and 50 wt% Ni-loaded catalysts improved the adsorption capacity and photocatalytic activity upon exposure to visible light, resulting in very effective removal of dye contaminants under visible light irradiation. Increasing the Ni content up to 40 and 50 wt% induced not only a structural change affording high porosity but also a narrowing of the band gap to 2.51 eV. Meanwhile, the presence of GO in the composite photocatalysts inhibited the agglomeration of Ni particles even at high Ni content, resulting in similar Ni particle sizes regardless of the Ni content. At the same time, Ni metal accelerated the reduction of the GO sheets, as evidenced by the Raman data.

  9. Prevention of cadmium bioaccumulation by herbal adaptogens

    OpenAIRE

    K Bharavi; A. Gopala Reddy; G S Rao; Ravi Kumar, P.; D Srinivas Kumar; P Prabhu Prasadini

    2011-01-01

    Objectives : To evaluate the effect of various herbal adaptogens such as shade-dried powders of Withania somnifera, Ocimum sanctum, Asperagus recemosus, Andrographis paniculata, Asphaltum panjabinum (Shilajith), Gymnema sylvestre, Spirulina platensis, and Panex ginseng on cadmium (Cd)-induced oxidative stress and its accumulation in broiler chicken. Materials and Methods : A total of 80 male broiler chicks of day old age were randomly assigned to 10 equal groups. Group 1 birds were fed wi...

  10. Influence of the Incorporation of Transition Metals on the Basicity of Mg,Al-Mixed Oxides and on Their Catalytic Properties for Transesterification of Vegetable Oils

    Directory of Open Access Journals (Sweden)

    Paula M. Veiga

    2013-01-01

    Full Text Available The transesterification of vegetable oils produces fatty acid methyl esters (biodiesel. Biodiesel is a nonpolluting alternative fuel produced from renewable resources whose chemical and physical properties closely resemble those of the petroleum diesel fuel and does not contribute to the greenhouse effect. The use of solid catalysts makes biodiesel production processes environmentally friendly. In this work, Mg,Al-mixed oxides derived from Mg,Al-hydrotalcite-like compound with an M3+/(M2++M3+ molar ratio of 0.25, in which Mg or Al was partially replaced by Co2+, Cu2+, Cr3+, or Fe3+, were prepared, characterized, and evaluated as catalysts for the transesterification of soybean oil with methanol. The results have indicated that the incorporation of transition metal influenced both textural and base properties. All the evaluated catalysts were active for the studied reaction. The catalytic activity followed the order Cr-MO < Co-MO < Cu-MO < Fe-MO < MO and could be explained by mesoporous volume.

  11. Plausible Mechanisms of Cadmium Carcinogenesis

    Science.gov (United States)

    Cadmium is a transition metal and an ubiquitous environmental and industrial pollutant. Laboratory animal studies and epidemiological studies have shown that exposure to cadmium is associated with various organ toxicities and carcinogenic effects. Several national and internation...

  12. Cadmium absorption inhibitors for soil

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, S.

    1974-05-25

    Cadmium absorption by soil is one cause of soil pollution. Cadmium adsorption inhibitors were prepared by mixing alginic acid which contained brown algae (Ascophyllum nodosum) and an inorganic material, shell fossils. This mixture was highly effective in preventing cadmium absorption by the soil.

  13. CATION EXCHANGER1 Cosegregates with Cadmium Tolerance in the Metal Hyperaccumulator Arabidopsis halleri and Plays a Role in Limiting Oxidative Stress in Arabidopsis Spp.

    Science.gov (United States)

    Baliardini, Cecilia; Meyer, Claire-Lise; Salis, Pietrino; Saumitou-Laprade, Pierre; Verbruggen, Nathalie

    2015-09-01

    Arabidopsis halleri is a model species for the study of plant adaptation to extreme metallic conditions. In this species, cadmium (Cd) tolerance seems to be constitutive, and the mechanisms underlying the trait are still poorly understood. A previous quantitative trait loci (QTL) analysis performed on A. halleri × Arabidopsis lyrata backcross population1 identified the metal-pump gene Heavy Metal ATPase4 as the major genetic determinant for Cd tolerance. However, although necessary, Heavy Metal ATPase4 alone is not sufficient for determining this trait. After fine mapping, a gene encoding a calcium(2+)/hydrogen(+) antiporter, cation/hydrogen(+) exchanger1 (CAX1), was identified as a candidate gene for the second QTL of Cd tolerance in A. halleri. Backcross population1 individuals displaying the A. halleri allele for the CAX1 locus exhibited significantly higher CAX1 expression levels compared with the ones with the A. lyrata allele, and a positive correlation between CAX1 expression and Cd tolerance was observed. Here, we show that this QTL is conditional and that it is only detectable at low external Ca concentration. CAX1 expression in both roots and shoots was higher in A. halleri than in the close Cd-sensitive relative species A. lyrata and Arabidopsis thaliana. Moreover, CAX1 loss of function in A. thaliana led to higher Cd sensitivity at low concentration of Ca, higher sensitivity to methylviologen, and stronger accumulation of reactive oxygen species after Cd treatment. Overall, this study identifies a unique genetic determinant of Cd tolerance in the metal hyperaccumulator A. halleri and offers a new twist for the function of CAX1 in plants. PMID:26162428

  14. CATION EXCHANGER1 Cosegregates with Cadmium Tolerance in the Metal Hyperaccumulator Arabidopsis halleri and Plays a Role in Limiting Oxidative Stress in Arabidopsis Spp.1[OPEN

    Science.gov (United States)

    Baliardini, Cecilia; Meyer, Claire-Lise; Salis, Pietrino; Saumitou-Laprade, Pierre; Verbruggen, Nathalie

    2015-01-01

    Arabidopsis halleri is a model species for the study of plant adaptation to extreme metallic conditions. In this species, cadmium (Cd) tolerance seems to be constitutive, and the mechanisms underlying the trait are still poorly understood. A previous quantitative trait loci (QTL) analysis performed on A. halleri × Arabidopsis lyrata backcross population1 identified the metal-pump gene Heavy Metal ATPase4 as the major genetic determinant for Cd tolerance. However, although necessary, Heavy Metal ATPase4 alone is not sufficient for determining this trait. After fine mapping, a gene encoding a calcium2+/hydrogen+ antiporter, cation/hydrogen+ exchanger1 (CAX1), was identified as a candidate gene for the second QTL of Cd tolerance in A. halleri. Backcross population1 individuals displaying the A. halleri allele for the CAX1 locus exhibited significantly higher CAX1 expression levels compared with the ones with the A. lyrata allele, and a positive correlation between CAX1 expression and Cd tolerance was observed. Here, we show that this QTL is conditional and that it is only detectable at low external Ca concentration. CAX1 expression in both roots and shoots was higher in A. halleri than in the close Cd-sensitive relative species A. lyrata and Arabidopsis thaliana. Moreover, CAX1 loss of function in A. thaliana led to higher Cd sensitivity at low concentration of Ca, higher sensitivity to methylviologen, and stronger accumulation of reactive oxygen species after Cd treatment. Overall, this study identifies a unique genetic determinant of Cd tolerance in the metal hyperaccumulator A. halleri and offers a new twist for the function of CAX1 in plants. PMID:26162428

  15. Characterization of heavy oxide inorganic scintillator crystals for direct detection of fast neutrons based on inelastic scattering

    OpenAIRE

    Rusiecki, Philip R.

    2015-01-01

    Approved for public release; distribution is unlimited Heavy oxide inorganic scintillators may prove viable in the detection of fast neutrons based on the mechanism of inelastic neutron scattering. A candidate set of crystals incorporating constituents of heavy atomic mass, namely bismuth germinate (BGO), zinc tungstate (ZWO), cadmium tungstate (CWO), lead tungstate (PWO), lutetium-gadolinium orthosilicate activated with cerium (LGSO:Ce) and lutetium-aluminum garnet with cerium (LuAG:Ce), ...

  16. Effect of abietic acid addition on anodic dissolution of zinc- cadmium- and thallium amalgams in sodium sulfate solution

    International Nuclear Information System (INIS)

    The method of inversion voltametry with a stationary mercury drop electrode has been applied to investigate the effect of abietic acid (AA) on anodic oxidation of cadmium, zinc, thallium from their amalgams as well as from mixed cadmium-thallium and zinc-thallium amalgams against the background of 0.5 M sodium sulfate at 298 K. Constants of peak of analgam anodic oxidation in the background solution and with additions of different AA concentrations are calculated. It is established that AA has the inhibiting effect on the processes of oxidation of cadmium- and zinc amalgams and does not produce the inhibiting effect on the oxidation of thallium amalgam

  17. Uptake and incorporation of {sup 15}N marked nitrogen oxides by seasonal and woddy plants; Aufnahme und Einbau {sup 15}N-markierter Stickoxide durch krautige und holzige Pflanzen

    Energy Technology Data Exchange (ETDEWEB)

    Eickriede, A.

    1998-07-01

    It the Research Centre Juelich a special system was developed to expose plants under defined climatic conditions to a nitrogen oxide enriched atmosphere. In completition and extension to former studies sunflowers (Helianthus annuus L.), mays (Zea mays L.) and poplar (Populus tremula x P. alba) were exposed to nitrogen oxides. By using {sup 15}N enriched nitrogen oxides ({sup 15}NO{sub 2}, and {sup 15}NO, summarised as {sup 15}NO{sub x}) the uptake and incorporation of {sup 15}NOx in dependance of the exposition concentration (30 to 100 ppb {sup 15}NO, 20 ppb {sup 15}NO{sub 2}), nitrogen nutrition (nitrate or ammonium), and harvesting time were examined. Moreover, the influence of nitrogen oxide exposition on the distribution pattern of {sup 15}NO{sub x} nitrogen within the plants and on the amino acid content of plant leaves was investigated. (orig.)

  18. Nrf2 activation prevents cadmium-induced acute liver injury

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kai C. [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie J. [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-15

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H{sub 2}DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice

  19. Nrf2 activation prevents cadmium-induced acute liver injury

    International Nuclear Information System (INIS)

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H2DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice were

  20. Metallomics and NMR-based metabolomics of Chlorella sp. reveal the synergistic role of copper and cadmium in multi-metal toxicity and oxidative stress.

    Science.gov (United States)

    Zhang, Wenlin; Tan, Nicole G J; Fu, Baohui; Li, Sam F Y

    2015-03-01

    Industrial wastewaters often contain high levels of metal mixtures, in which metal mixtures may have synergistic or antagonistic effects on aquatic organisms. A combination of metallomics and nuclear magnetic resonance spectroscopy (NMR)-based metabolomics was employed to understand the consequences of multi-metal systems (Cu, Cd, Pb) on freshwater microalgae. Morphological characterization, cell viability and chlorophyll a determination of metal-spiked Chlorella sp. suggested synergistic effects of Cu and Cd on growth inhibition and toxicity. While Pb has no apparent effect on Chlorella sp. metabolome, a substantial decrease of sucrose, amino acid content and glycerophospholipid precursors in Cu-spiked microalgae revealed Cu-induced oxidative stress. Addition of Cd to Cu-spiked cultures induced more drastic metabolic perturbations, hence we confirmed that Cu and Cd synergistically influenced photosynthesis inhibition, oxidative stress and membrane degradation. Total elemental analysis revealed a significant decrease in K, and an increase in Na, Mg, Zn and Mn concentrations in Cu-spiked cultures. This indicated that Cu is more toxic to Chlorella sp. as compared to Cd or Pb, and the combination of Cu and Cd has a strong synergistic effect on Chlorella sp. oxidative stress induction. Oxidative stress is confirmed by liquid chromatography tandem mass spectrometry analysis, which demonstrated a drastic decrease in the GSH/GSSG ratio solely in Cu-spiked cultures. Interestingly, we observed Cu-facilitated Cd and Pb bioconcentration in Chlorella sp. The absence of phytochelatins and an increment of extracellular polymeric substances (EPS) yields in Cu-spiked cultures suggested that the mode of bioconcentration of Cd and Pb is through adsorption of free metals onto the algal EPS rather than intracellular chelation to phytochelatins.

  1. Cadmium(Cd)-induced oxidative stress down-regulates the gene expression of DNA mismatch recognition proteins MutS homolog 2 (MSH2) and MSH6 in zebrafish (Danio rerio) embryos

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Todd, E-mail: toddhsu@mail.ntou.edu.tw [Institute of Bioscience and Biotechnology and Center of Excellence for Marine Bioenvironment and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan (China); Huang, Kuan-Ming; Tsai, Huei-Ting; Sung, Shih-Tsung; Ho, Tsung-Nan [Institute of Bioscience and Biotechnology and Center of Excellence for Marine Bioenvironment and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan (China)

    2013-01-15

    DNA mismatch repair (MMR) of simple base mismatches and small insertion-deletion loops in eukaryotes is initiated by the binding of the MutS homolog 2 (MSH2)-MSH6 heterodimer to mismatched DNA. Cadmium (Cd) is a genotoxic heavy metal that has been recognized as a human carcinogen. Oxidant stress and inhibition of DNA repair have been proposed as major factors underlying Cd genotoxicity. Our previous studies indicated the ability of Cd to disturb the gene expression of MSH6 in zebrafish (Danio rerio) embryos. This study was undertaken to explore if Cd-induced oxidative stress down-regulated MSH gene activities. Following the exposure of zebrafish embryos at 1 h post fertilization (hpf) to sublethal concentrations of Cd at 3-5 {mu}M for 4 or 9 h, a parallel down-regulation of MSH2, MSH6 and Cu/Zn superoxide dismutase (Cu/Zn-SOD) gene expression was detected by real-time RT-PCR and the expression levels were 40-50% of control after a 9-h exposure. Cd exposure also induced oxidative stress, yet no inhibition of catalase gene activity was observed. Whole mount in situ hybridization revealed a wide distribution of msh6 mRNA in the head regions of 10 hpf embryos and pretreatment of embryos with antioxidants butylhydroxytoluene (BHT), D-mannitol or N-acetylcysteine (NAC) at 1-10 {mu}M restored Cd-suppressed msh6 expression. QPCR confirmed the protective effects of antioxidants on Cd-suppressed msh2/msh6 mRNA production. Down-regulated MSH gene activities reaching about 50% of control were also induced in embryos exposed to paraquat, a reactive oxygen species (ROS)-generating herbicide, or hydrogen peroxide at 200 {mu}M. Hence, Cd at sublethal levels down-regulates msh2/msh6 expression primarily via ROS as signaling molecules. The transcriptional activation of human msh6 is known to be fully dependent on the specificity factor 1 (Sp1). Cd failed to inhibit the DNA binding activity of zebrafish Sp1 unless at lethal concentrations based on band shift assay, therefore

  2. Gene expression analysis in rat lungs after intratracheal exposure to nanoparticles doped with cadmium

    Science.gov (United States)

    Coccini, Teresa; Fabbri, Marco; Roda, Elisa; Grazia Sacco, Maria; Manzo, Luigi; Gribaldo, Laura

    2011-07-01

    Silica nanoparticles (NPs) incorporating cadmium (Cd) have been developed for a range of potential application including drug delivery devices. Occupational Cd inhalation has been associated with emphysema, pulmonary fibrosis and lung tumours. Mechanistically, Cd can induce oxidative stress and mediate cell-signalling pathways that are involved in inflammation.This in vivo study aimed at investigating pulmonary molecular effects of NPs doped with Cd (NP-Cd, 1 mg/animal) compared to soluble CdCl2 (400 μg/animal), in Sprague Dawley rats treated intra-tracheally, 7 and 30 days after administration. NPs of silica containing Cd salt were prepared starting from commercial nano-size silica powder (HiSil™ T700 Degussa) with average pore size of 20 nm and surface area of 240 m2/g. Toxicogenomic analysis was performed by the DNA microarray technology (using Agilent Whole Rat Genome Microarray 4×44K) to evaluate changes in gene expression of the entire genome. These findings indicate that the whole genome analysis may represent a valuable approach to assess the whole spectrum of biological responses to cadmium containing nanomaterials.

  3. Gene expression analysis in rat lungs after intratracheal exposure to nanoparticles doped with cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Coccini, Teresa; Manzo, Luigi [Toxicology Division, Salvatore Maugeri Foundation IRCCS, Pavia (Italy); Fabbri, Marco; Sacco, Maria Grazia; Gribaldo, Laura [European Commission, Joint Research Centre, IHCP- 21027 Ispra (Italy); Roda, Elisa [European Centre for Nanomedicine, University of Pavia, 27100 Pavia (Italy)

    2011-07-06

    Silica nanoparticles (NPs) incorporating cadmium (Cd) have been developed for a range of potential application including drug delivery devices. Occupational Cd inhalation has been associated with emphysema, pulmonary fibrosis and lung tumours. Mechanistically, Cd can induce oxidative stress and mediate cell-signalling pathways that are involved in inflammation.This in vivo study aimed at investigating pulmonary molecular effects of NPs doped with Cd (NP-Cd, 1 mg/animal) compared to soluble CdCl{sub 2} (400 {mu}g/animal), in Sprague Dawley rats treated intra-tracheally, 7 and 30 days after administration. NPs of silica containing Cd salt were prepared starting from commercial nano-size silica powder (HiSil{sup TM} T700 Degussa) with average pore size of 20 nm and surface area of 240 m{sup 2}/g. Toxicogenomic analysis was performed by the DNA microarray technology (using Agilent Whole Rat Genome Microarray 4x44K) to evaluate changes in gene expression of the entire genome. These findings indicate that the whole genome analysis may represent a valuable approach to assess the whole spectrum of biological responses to cadmium containing nanomaterials.

  4. Removal of hydrogen sulfide at ambient conditions on cadmium/GO-based composite adsorbents.

    Science.gov (United States)

    Florent, Marc; Wallace, Rajiv; Bandosz, Teresa J

    2015-06-15

    Cadmium-based materials with various hydroxide to carbonate ratios and their composites with graphite oxide were synthesized by a fast and simple precipitation procedure and then used as H2S adsorbents at ambient conditions in the dark or upon a visible light exposure. The structural properties and chemical features of the adsorbents were analyzed before and after hydrogen sulfide adsorption. The results showed that the high ratio of hydroxide to carbonate led to an improved H2S adsorption capacity. In moist conditions cadmium hydroxide was the best adsorbent. Moreover, it showed photoactive properties. While the incorporation of a graphene-based phase slightly decreased the extent of the improvement in the H2S adsorption capacity in moist conditions caused by photoactivity, its presence in the composites enhanced the performance in dry conditions. This was linked to photoactivity of CdS that can split H2S resulting in the formation of water in the system. The graphene-based phase enhanced the electron transfer and delayed the recombination of photoinduced charges. Carbonate-based materials showed a very good adsorption capacity in dark conditions in the presence of moisture. Upon the light exposure, CdS likely photocatalyzes the reduction of carbonate ions to formates/formaldehydes. Their deposition on the surface limits the number of sites available to H2S adsorption. PMID:25792480

  5. Effects of time, soil organic matter, and iron oxides on the relative retention and redistribution of lead, cadmium, and copper on soils.

    Science.gov (United States)

    Diagboya, Paul N; Olu-Owolabi, Bamidele I; Adebowale, Kayode O

    2015-07-01

    In order to predict the bioavailability of toxic metals in soils undergoing degradation of organic matter (OM) and iron oxides (IOs), it is vital to understand the roles of these soil components in relation to metal retention and redistribution with time. In this present work, batch competitive sorptions of Pb(II), Cu(II), and Cd(II) were investigated between 1 and 90 days. Results showed that competition affected Cd(II) sorption more than Cu(II) and Pb(II). The sorption followed the trend Pb(II) > > Cu(II) > Cd(II), irrespective of aging, and this high preference for Pb(II) ions in soils reduced with time. Removal of OM led to reduction in distribution coefficient (K d) values of ≈33% for all cations within the first day. However, K d increased nearly 100% after 7 days and over 1000% after 90-day period. The enhanced K d values indicated that sorptions occurred on the long run on surfaces which were masked by OM. Removal of IO caused selective increases in the K d values, but this was dependent on the dominant soil constituent(s) in the absence of IO. The K d values of the IO-degraded samples nearly remained constant irrespective of aging indicating that sorptions on soil components other than the IO are nearly instantaneous while iron oxides played greater role than other constituents with time. Hence, in the soils studied, organic matter content determines the immediate relative metal retention while iron oxides determine the redistribution of metals with time.

  6. Protective role of carnosine in mice with cadmium-induced acute hepatotoxicity.

    Science.gov (United States)

    Fouad, Amr A; Qureshi, Habib A; Yacoubi, Mohamed T; Al-Melhim, Walid N

    2009-11-01

    The hepatoprotective effect of carnosine was investigated against cadmium-induced acute liver injury in mice. Hepatotoxicity was induced by a single i.p. injection of cadmium chloride (6.5mg/kg). Carnosine treatment (10mg/kg/day, i.p.) was applied for three consecutive days, starting one day before cadmium administration. Carnosine significantly decreased the cadmium-induced elevations in serum aminotransferases. Carnosine suppressed lipid peroxidation and restored the deficits in the antioxidant defense mechanisms (reduced glutathione level, and catalase and superoxide dismutase activities) in liver tissue resulted from cadmium administration. Also, the reductions in hepatic nitric oxide and zinc ion levels, and the increases in hepatic cadmium ion concentration, and myeloperoxidase and caspase-3 activities following cadmium exposure were significantly attenuated by carnosine treatment. In addition, carnosine markedly ameliorated cadmium-induced liver tissue damage as evidenced by light and electron microscopic examinations. It was concluded that carnosine can be considered a potential candidate to protect the liver against the deleterious effect of acute cadmium intoxication. PMID:19748544

  7. Different effects of sodium chloride preincubation on cadmium tolerance of Pichia kudriavzevii and Saccharomyces cerevisiae.

    Science.gov (United States)

    Ma, Ning; Li, Chunsheng; Dong, Xiaoyan; Wang, Dongfeng; Xu, Ying

    2015-08-01

    Application of growing microorganisms for cadmium removal is restricted by high cadmium toxicity. The effects of sodium chloride (NaCl) preincubation on the cadmium tolerance and removal ability of Pichia kudriavzevii and Saccharomyces cerevisiae were investigated in this study. NaCl preincubation improved the biomass of P. kudriavzevii under cadmium stress, while no obvious effect was observed in S. cerevisiae. The improved activities of peroxidase (POD) and catalase (CAT) after NaCl preincubation might be an important reason for the decrease of the reactive oxygen species (ROS) accumulation, cell death, and oxidative damage of proteins and lipids induced by cadmium, contributing to the improvement of the yeast growth. The cadmium bioaccumulation capacity of P. kudriavzevii decreased significantly after NaCl preincubation, which played an important role in mitigating the cadmium toxicity to the yeast. The cadmium removal rate of P. kudriavzevii was obviously higher than S. cerevisiae and was significantly enhanced after NaCl preincubation. The results suggested that NaCl preincubation improved the cadmium tolerance and removal ability of P. kudriavzevii. PMID:25721585

  8. Cadmium induces apoptosis in pancreatic β-cells through a mitochondria-dependent pathway: the role of oxidative stress-mediated c-Jun N-terminal kinase activation.

    Directory of Open Access Journals (Sweden)

    Kai-Chih Chang

    Full Text Available Cadmium (Cd, one of well-known highly toxic environmental and industrial pollutants, causes a number of adverse health effects and diseases in humans. The growing epidemiological studies have suggested a possible link between Cd exposure and diabetes mellitus (DM. However, the toxicological effects and underlying mechanisms of Cd-induced pancreatic β-cell injury are still unknown. In this study, we found that Cd significantly decreased cell viability, and increased sub-G1 hypodiploid cells and annexin V-Cy3 binding in pancreatic β-cell-derived RIN-m5F cells. Cd also increased intracellular reactive oxygen species (ROS generation and malondialdehyde (MDA production and induced mitochondrial dysfunction (the loss of mitochondrial membrane potential (MMP and the increase of cytosolic cytochrome c release, the decreased Bcl-2 expression, increased p53 expression, poly (ADP-ribose polymerase (PARP cleavage, and caspase cascades, which accompanied with intracellular Cd accumulation. Pretreatment with the antioxidant N-acetylcysteine (NAC effectively reversed these Cd-induced events. Furthermore, exposure to Cd induced the phosphorylations of c-jun N-terminal kinases (JNK, extracellular signal-regulated kinases (ERK1/2, and p38-mitogen-activated protein kinase (MAPK, which was prevented by NAC. Additionally, the specific JNK inhibitor SP600125 or JNK-specific small interference RNA (si-RNA transfection suppressed Cd-induced β-cell apoptosis and related signals, but not ERK1/2 and p38-MAPK inhibitors (PD98059 and SB203580 did not. However, the JNK inhibitor or JNK-specific si-RNA did not suppress ROS generation in Cd-treated cells. These results indicate that Cd induces pancreatic β-cell death via an oxidative stress downstream-mediated JNK activation-triggered mitochondria-regulated apoptotic pathway.

  9. in situ immobilization of Cadmium and zinc in contaminated soils

    NARCIS (Netherlands)

    Osté, L.A.

    2001-01-01

    Keywords: beringite, cadmium, DOC, DOM, earthworms, immobilization, leaching, lime, manganese oxides, metal binding, metal uptake, organic matter partitioning, pH, soil contamination, remediation, sorption, Swiss chard, zeolites, zinc.It is generally assumed that a decrease in metal c

  10. Cadmium in Sweden - environmental risks

    Energy Technology Data Exchange (ETDEWEB)

    Parkman, H.; Iverfeldt, Aa. [Swedish Environmental Research Inst. (Sweden); Borg, H.; Lithner, G. [Stockholm Univ. (Sweden). Inst. for Applied Environmental Research

    1998-03-01

    This report aims at assessing possible effects of cadmium in the Swedish environment. Swedish soils and soft freshwater systems are, due to a generally poor buffering capacity, severely affected by acidification. In addition, the low salinity in the Baltic Sea imply a naturally poor organism structure, with some important organisms living close to their limit of physiological tolerance. Cadmium in soils is mobilized at low pH, and the availability and toxicity of cadmium in marine systems are enhanced at low salinity. The Swedish environment is therefore extra vulnerable to cadmium pollution. The average concentrations of cadmium in the forest mor layers, agricultural soils, and fresh-waters in Sweden are enhanced compared to `back-ground concentrations`, with a general increasing trend from the north to the south-west, indicating strong impact of atmospheric deposition of cadmium originating from the central parts of Europe. In Swedish sea water, total cadmium concentrations, and the fraction of bio-available `free` cadmium, generally increases with decreasing salinity. Decreased emissions of cadmium to the environment have led to decreasing atmospheric deposition during the last decade. The net accumulation of cadmium in the forest mor layer has stopped, and even started to decrease. In northern Sweden, this is due to the decreased deposition, but in southern Sweden the main reason is increased leakage of cadmium from the topsoil as a consequence of acidification. As a result, cadmium in the Swedish environments is undergoing an extended redistribution between different soil compartments, and from the soils to the aquatic systems. 90 refs, 23 figs, 2 tabs. With 3 page summary in Swedish

  11. Dithizone-modified graphene oxide nano-sheet as a sorbent for pre-concentration and determination of cadmium and lead ions in food.

    Science.gov (United States)

    Moghadam Zadeh, Hamid Reza; Ahmadvand, Parvaneh; Behbahani, Ali; Amini, Mostafa M; Sayar, Omid

    2015-01-01

    Graphene oxide nano-sheet was modified with dithizone as a novel sorbent for selective pre-concentration and determination of Cd(II) and Pb(II) in food. The sorbent was characterised by various analytical methods and the effective parameters for Cd(II) and Pb(II) adsorption were optimised during this work. The high adsorption capacity and selectivity of this sorbent makes the method capable of fast determinations of the Cd(II) and Pb(II) content in complicated matrices even at μg l(-1) levels using commonly available instrumentation. The precision of this method was method was applied to the determination of Cd(II) and Pb(II) ions in common food samples and satisfactory results were obtained. PMID:26179656

  12. CADMIUM – ENVIRONMENTAL HAZARD

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-06-01

    Full Text Available The paper presents some information about current status of cadmium as an environmental health problem. Agricultural uses of phosphate fertilizers, sewage sludge and industrial uses of Cd are the major source of widespread of this metal at trace levels into the general environment and human foodstuffs. It is well known that high cadmium (Cd exposure causes renal damage, anemia, enteropathy, osteoporosis, osteomalacia, whereas the dose-response relationship at low levels exposure is less established. During the last decade an increasing number of studies have found an adverse health effects due to low environmental exposure to Cd. Many authors try to determine the relationship between Cd intake and Cd toxicity indicators, especially dealing renal tubular damage. The level of b2-microglobulin in urine is regarded as the most sensitive biomarker of renal disfunction due to low environmental Cd concentrations.

  13. Cadmium sulfite hexahydrate revisited

    Directory of Open Access Journals (Sweden)

    Sergio Baggio

    2008-07-01

    Full Text Available The present structural revision of the title compound, tetracadmium tetrasulfite hexahydrate, [Cd4(SO34(H2O5]·H2O, is a low-temperature upgrade (T = 100 K and R = 0.017 of the original room-temperature structure reported by Kiers & Vos [Cryst. Struct. Commun. (1978. 7, 399–403; T = 293 K and R = 0.080. The compound is a three-dimensional polymer with four independent cadmium centres, four sulfite anions and six water molecules, five of them coordinated to two cadmium centres and the remaining one an unbound solvent molecule which completes the asymmetric unit. There are two types of cadmium environment: CdO8 (through four chelating sulfite ligands and CdO6 (by way of six monocoordinated ligands. The former groups form planar arrays [parallel to (001 and separated by half a unit cell translation along c], made up of chains running along [110] and [overline{1}10], respectively. These chains are, in turn, interconnected both in an intraplanar as well as in an interplanar fashion by the latter CdO6 polyhedra into a tight three-dimensional framework. There is, in addition, an extensive network of hydrogen bonds, in which all 12 water H atoms act as donors and eight O atoms from all four sulfite groups and two water molecules act as acceptors.

  14. Subcellular partitioning kinetics, metallothionein response and oxidative damage in the marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dots.

    Science.gov (United States)

    Rocha, Thiago Lopes; Gomes, Tânia; Durigon, Emerson Giuliani; Bebianno, Maria João

    2016-06-01

    The environmental health impact of metal-based nanomaterials is of emerging concern, but their metabolism and detoxification pathways in marine bioindicator species remain unclear. This study investigated the role of subcellular partitioning kinetics, metallothioneins (MTs) response and oxidative damage (lipid peroxidation - LPO) in the marine mussel Mytilus galloprovincialis exposed to CdTe quantum dots (QDs) in comparison with its dissolved counterpart. Mussels were exposed to QDs and dissolved Cd for 21 days at 10 μg Cd L(-1) followed by a 50 days depuration. Higher Cd concentrations were detected in fractions containing mitochondria, nucleus and lysosomes, suggesting potential subcellular targets of QDs toxicity in mussel tissues. Tissue specific metabolism patterns were observed in mussels exposed to both Cd forms. Although MT levels were directly associated with Cd in both forms, QDs subcellular partitioning is linked to biologically active metal (BAM), but no increase in LPO occurred, while in the case of dissolved Cd levels are in the biologically detoxified metal (BDM) form, indicating nano-specific effects. Mussel gills showed lower detoxification capability of QDs, while the digestive gland is the major tissue for storage and detoxification of both Cd forms. Both mussel tissues were unable to completely eliminate the Cd accumulated in the QDs form (estimated half-life time>50 days), highlighting the potential source of Cd and QDs toxicity for human and environmental health. Results indicate tissue specific metabolism patterns and nano-specific effects in marine mussel exposed to QDs. PMID:26950627

  15. Subcellular partitioning kinetics, metallothionein response and oxidative damage in the marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dots.

    Science.gov (United States)

    Rocha, Thiago Lopes; Gomes, Tânia; Durigon, Emerson Giuliani; Bebianno, Maria João

    2016-06-01

    The environmental health impact of metal-based nanomaterials is of emerging concern, but their metabolism and detoxification pathways in marine bioindicator species remain unclear. This study investigated the role of subcellular partitioning kinetics, metallothioneins (MTs) response and oxidative damage (lipid peroxidation - LPO) in the marine mussel Mytilus galloprovincialis exposed to CdTe quantum dots (QDs) in comparison with its dissolved counterpart. Mussels were exposed to QDs and dissolved Cd for 21 days at 10 μg Cd L(-1) followed by a 50 days depuration. Higher Cd concentrations were detected in fractions containing mitochondria, nucleus and lysosomes, suggesting potential subcellular targets of QDs toxicity in mussel tissues. Tissue specific metabolism patterns were observed in mussels exposed to both Cd forms. Although MT levels were directly associated with Cd in both forms, QDs subcellular partitioning is linked to biologically active metal (BAM), but no increase in LPO occurred, while in the case of dissolved Cd levels are in the biologically detoxified metal (BDM) form, indicating nano-specific effects. Mussel gills showed lower detoxification capability of QDs, while the digestive gland is the major tissue for storage and detoxification of both Cd forms. Both mussel tissues were unable to completely eliminate the Cd accumulated in the QDs form (estimated half-life time>50 days), highlighting the potential source of Cd and QDs toxicity for human and environmental health. Results indicate tissue specific metabolism patterns and nano-specific effects in marine mussel exposed to QDs.

  16. 水稻土甲烷氧化菌对镉胁迫的响应%Response of methanotrophic community structure and oxidation potential to cadmium stress in a Chinese paddy soil

    Institute of Scientific and Technical Information of China (English)

    郑勇; 郑袁明; 贺纪正

    2012-01-01

    重金属污染影响土壤微生物群落结构与活性,间接影响土壤碳(如CO2、CH4)的生物地球化学循环和全球气候变化.甲烷氧化菌氧化消耗CH4,降低大气中CH4含量,在缓解由温室气体导致的全球温暖化方面起着重要作用.本研究通过短期土壤培养实验,比较研究了不同强度重金属镉(Cd)胁迫下,水稻土中甲烷氧化菌的多度、群落组成及其氧化CH4潜势的差异.结果表明,添加Cd含量越大,水稻土氧化CH4潜势越弱,甲烷氧化菌pmoA基因拷贝数显著减少;甲烷氧化菌多度与水稻土氧化CH4潜势之间存在显著正相关关系(P< 0.001).群落组成分析发现,在相对低含量Cd(1 mg·kg-1)条件下,有新的甲烷氧化菌菌属出现,而添加较高含量Cd (10 mg·kg-1)时甲烷氧化菌种类减少.总之,Cd胁迫降低水稻土中甲烷氧化菌多样性及其氧化CH4潜势,可能导致原位CH4消耗减少,从而增加稻田CH4排放.%Heavy metal contamination has strong effect on the soil microbial community and activities, and also affects the biogeochemical cycling of soil carbon (e.g. CO2 and CH4) and global climate change. Fortunately, methane-oxidizing bacteria (methanotrophs) can consume CH4 and therefore play a critical role in the mitigation of global warming. Here, a short-term, laboratory-based incubation experiment was conducted to examine the effects of cadmium (Cd) amendments on the abundance, community composition and oxidation potential of methanotrophs in a southern China paddy soil. The results showed that there were significantly lower methanotrophic oxidation potential and abundance in the treatment of Cd amendment of 10 mg·kg-1 (high-Cd) than those in the treatment of Cd amendment of 1 mg·kg-1 (low-Cd) dry weight soil and the Control. Correlation analyses indicated that the methanotrophic oxidation potentials were significantly positively correlated with the abundance of methanotrophs (P < 0.001). For the community in rice

  17. The protective effect of Physalis peruviana L. against cadmium-induced neurotoxicity in rats.

    Science.gov (United States)

    Abdel Moneim, Ahmed E; Bauomy, Amira A; Diab, Marwa M S; Shata, Mohamed Tarek M; Al-Olayan, Ebtesam M; El-Khadragy, Manal F

    2014-09-01

    The present study was carried out to investigate the protective effect of Physalis peruviana L. (family Solanaceae) against cadmium-induced neurotoxicity in rats. Adult male Wistar rats were randomly divided into four groups. Group 1 was used as control. Group 2 was intraperitoneally injected with 6.5 mg/kg bwt of cadmium chloride for 5 days. Group 3 was treated with 200 mg/kg bwt of methanolic extract of Physalis (MEPh). Group 4 was pretreated with MEPh 1 h before cadmium for 5 days. Cadmium treatment induced marked disturbances in neurochemical parameters as indicating by significant (p Physalis has a beneficial effect in ameliorating the cadmium-induced oxidative neurotoxicity in the brain of rats. PMID:25022246

  18. Cadmium in blood and hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Eum, Ki-Do; Lee, Mi-Sun [Department of Environmental Health, Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul (Korea, Republic of); Paek, Domyung [Department of Environmental Health, Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul (Korea, Republic of)], E-mail: paekdm@snu.ac.kr

    2008-12-15

    Objectives:: This study is to examine the effect of cadmium exposure on blood pressure in Korean general population. Methods:: The study population consisted of 958 men and 944 women who participated in the 2005 Korean National Health and Nutrition Examination Survey (KNHANES), in which blood pressure and blood cadmium were measured from each participant. Results:: The mean blood cadmium level was 1.67 {mu}g/L (median level 1.55). The prevalence of hypertension was 26.2%. The blood cadmium level was significantly higher among those subjects with hypertension than those without (mean level 1.77 versus 1.64 {mu}g/dL). After adjusting for covariates, the odds ratio of hypertension comparing the highest to the lowest tertile of cadmium in blood was 1.51 (95% confidence interval 1.13 to 2.05), and a dose-response relationship was observed. Systolic, diastolic, and mean arterial blood pressure were all positively associated with blood cadmium level, and this effect of cadmium on blood pressure was markedly stronger when the kidney function was reduced. Conclusions:: Cadmium exposures at the current level may have increased the blood pressure of Korean general population.

  19. Projectbeschrijving Cadmium-informatiepunt (CIP)

    NARCIS (Netherlands)

    Meijer PJ

    1989-01-01

    To minimize the use of cadmium the Central Government has decided to perform the purchase of products and materials within the Central Government as much as possible within the Draft Cadmium Decree. The activities to achieve this are as far as could be seen at the start of the project in june 19

  20. Projectbeschrijving Cadmium-informatiepunt (CIP)

    OpenAIRE

    Meijer PJ

    1989-01-01

    To minimize the use of cadmium the Central Government has decided to perform the purchase of products and materials within the Central Government as much as possible within the Draft Cadmium Decree. The activities to achieve this are as far as could be seen at the start of the project in june 1989, mentioned in this report.

  1. 铜、镉毒害对番茄生长和膜功能蛋白酶活性的影响及外源NO的缓解效应%Responses of growth, functional enzyme activity in biomembrane of tomato seedlings to excessive copper, cadmium and the alleviating effect of exogenous nitric oxide

    Institute of Scientific and Technical Information of China (English)

    崔秀敏; 吴小宾; 李晓云; 李絮花

    2011-01-01

    The effects of the toxicity of copper, cadmium (5 μmol/L and 50 μ mol/L) on tomato seedlings growth and physiological and biochemical characteristics were investigated, using nutrient solution culture in greenhouse in this study.The testing indices included copper and cadmium contents, root activity, nitrate reductase activity, photosynthetic characteristics, ATPase and H+ -PPase activities in biomembrane.The alleviating effect of exogenous nitric oxide under copper, cadmium stress was also discussed preliminarily.The results showed that copper, cadmium stress significantly restrained tomato growth.With the increase of stress degree, root activity and nitrate reductase activity declined dramatically, and the appearance of plant turned into worse.The copper, cadmium stress had a more severe effect on ion adsorption in roots than in leaves, particularly for copper.Copper stress at 50 μ mol/L increased copper content by 12 times in tomato roots, but had no effect on cadmium content.The cadmium stress reduced copper absorption.The copper, cadmium stress dramatically decreased net photosynthetic rate ( Pn), transpiration rate (Tr), and stomatal conductance (Gs), while enhanced the intercellular CO2 concentration (Ci).The copper, cadmium stress (50 μmol/L) also remarkably depressed the activities of H +-ATPase、Ca2+-ATPase in plasma membrane of leaves and roots, and the activities of H+-ATPase、Ca2+-ATPase and H+-PPase in root vacuolar membrane, indicating the response time and location of function protein of biological membrane to copper and cadmium stress varied with stress levels.Copper toxicity damaged more on the plasma membrane, while cadmium toxicity injured more on vacuolar membrane.Addition of 100 μmol/L SNP ( a NO donor) could significantly alleviate the inhibitory effects induced by excessive copper, cadmium, and increased the total absorption of copper and cadmium.%为探讨外源NO(SNP为供体)对50 μmol/L铜、镉毒害的缓解效应,采用营养

  2. 29 CFR 1926.1127 - Cadmium.

    Science.gov (United States)

    2010-07-01

    ... containment of cadmium or materials containing cadmium on the site or location at which construction...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1127 Cadmium. (a... forms, in all construction work where an employee may potentially be exposed to cadmium....

  3. Cadmium exposure in the Swedish environment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This report gives a thorough description of cadmium in the Swedish environment. It comprises three parts: Cadmium in Sweden - environmental risks;, Cadmium in goods - contribution to environmental exposure;, and Cadmium in fertilizers, soil, crops and foods - the Swedish situation. Separate abstracts have been prepared for all three parts

  4. Electrical conductivity of oxides from molten state to glassy. Effect on the incorporation of RuO{sub 2} particles; Conductivite electrique des verres et fontes d'oxides. Effets de l'incorporation de particules RuO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Simonnet, C

    2004-07-01

    This study concerns the electrical conductivity of oxides from molten state to glassy state and, in particular, the effect of the incorporation of RuO{sub 2} particles in the context of vitrification of radioactive waste. The material of interest in the nuclear field is basically a viscous or vitreous borosilicate containing a dispersion of RuO{sub 2} microcrystals. A very simple model of this heterogeneous material has been studied in particular (SiO{sub 2}, B{sub 2}O{sub 3}, Na{sub 2}O, RuO{sub 2}). An original method of impedance measurement in the liquid at high temperature yields reliable electrical conductivity values over a temperature range covering the liquid and vitreous phases of the borosilicates studied. In the borosilicate matrix, alkaline transport is mainly responsible for the ionic conduction. The temperature dependence of the conductivity may thus be represented by an equation combining a VFT law and an Arrhenius law to represent the electrical conductivity above and below T{sub g}. Beyond a critical volume fraction V{sub c} {approx} 0.01 of RuO{sub 2}, an electronic contribution is added to the ionic contribution of the matrix and the electrical conductivity increases significantly with the RuO{sub 2} content. This effect is described in terms of electrical percolation of the particle network. An electronic mechanism by tunnel transfer between particles is demonstrated. A mathematical model is developed to describe this mechanism in the solid composite. Beyond T{sub g}, conduction by the tunnel effect persists and the partial solubilization of RuO{sub 2} appears to be mainly responsible for the significant increase in electronic conductivity with the temperature. (author)

  5. Ameliorating Effects of Exogenous Nitric Oxide on Ryegrass Seedlings under Cadmium Stress%外源NO对镉胁迫下黑麦草生长的缓解效应

    Institute of Scientific and Technical Information of China (English)

    王全辉; 梁雪; 董元杰; 张秀玮; 刘春生

    2012-01-01

    为研究外源NO对Cd胁迫下黑麦草生长的缓解效应,采用营养液培养,研究了不同浓度硝普钠对100μmol/L CdCl2胁迫下黑麦草生理特性的影响.结果表明,SNP能显著缓解Cd胁迫对黑麦草植株造成的伤害,可明显提高黑麦草的生长量、叶绿素含量、脯氨酸( Pro)含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs),降低过氧化氢(H2O2)含量、超氧阴离子(O2-)产生速率、胞间CO2浓度(Ci);抑制了Cd向地上部的转运,与100 μmol/L SNP处理相比,50、200和400μmol/L SNP处理对黑麦草Cd胁迫的缓解作用明显降低.说明适宜浓度的外源NO作为化学诱抗剂,可以诱导黑麦草的抗逆性的增强,减轻和缓解Cd胁迫的伤害.%The aim of the experiment was to study the ameliorating effects of exogenous nitric oxide on growth of ryegrass seedlings under cadmium stress. A hydroponic experiment was conducted to investigate the effects of different concentrations of sodium nitroprusside (SNP), a NO donor, on physiological characteristics of ryegrass under 100 fimol/L CdCU stress. The results showed that exogenous sodium nitroprusside (SNP) significantly alleviated the stress damage to ryegrass under 100 /*mol/L CdCl2 stress, and increased the growth amount, the contents of chlorophyll and proline, the net photosynthetic rate (Pn), the transpiration rate (Tr), the stomata conductance (Gs), reduced H2O2 content, O2 ? - generation rate, intercellular CO2 concentration (Ci), significantly inhibit the transportation of Cd from root to shoot. When treated with 50 or 200 or 400 fxmol/L of SNP, ameliorating effects on ryegrass were obviously decreased compared with 100 jJtmol/L of SNP treatment. It is proposed that exogenous NO as chemical activator could induce stress resistance, and alleviate damage degree of Cd stress to ryegrass seedlings.

  6. Cadmium in newborns

    OpenAIRE

    Eklund, Gunilla

    2003-01-01

    Cadmium (Cd) is a well-known nephrotoxic environmental contaminant but there are indications that the developing nervous system might be even more sensitive to Cd than the kidneys in adults. Infants are exposed to Cd from various formulas and infant diets and the gastrointestinal Cd uptake is believed to be higher in newborns than in adults. Cd levels monitored in infant foods ranged between 0.74 and 27.0 µg/kg. Cow's milk formulas had the lowest levels and cereal-based formulas had up to 21 ...

  7. Lactobacillus plantarum L67 glycoprotein protects against cadmium chloride toxicity in RAW 264.7 cells.

    Science.gov (United States)

    Song, Sooyeon; Oh, Sejong; Lim, Kye-Taek

    2016-03-01

    The food and water we consume may be contaminated with a range of chemicals and heavy metals, such as lead, cadmium, arsenic, chromium, and mercury by accumulation through the food chain. Cadmium is known to be one of the major components in cigarette smoke and can cause lesions in many organs. Some lactobacilli can bind and remove heavy metals such as cadmium, lead, and copper. However, the mechanisms of cadmium toxicity and inhibition by probiotics are not clear. In this study, we demonstrated that glycoprotein (18 kDa) isolated from Lactobacillus plantarum L67 protected RAW 264.7 cells from expression of inflammation-related factors stimulated by cadmium chloride (100 µM). Furthermore, we evaluated the cytotoxicity of cadmium using the MTT assay and intracellular Ca(2+) using fluorescence, and assessed activities of activator protein kinase C (PKC-α), inducible nitric oxide synthase, activator protein (AP)-1, and mitogen-activated protein kinases using immunoblot. Our results indicated that glycoprotein isolated from L. plantarum L67 inhibited intracellular Ca(2+) mobilization. It also significantly suppressed inflammatory factors such as AP-1 (c-Jun and c-Fos), mitogen-activated protein kinases (ERK, JNK, and p38), and inducible nitric oxide synthase. Our findings suggest that the 24-kDa glycoprotein isolated from L. plantarum L67 might be used as a food component for protection of inflammation caused by cadmium ion.

  8. Cadmium Accumulation and DNA Homology with Metal Resistance Genes in Sulfate-Reducing Bacteria

    OpenAIRE

    Naz, Naghma; Young, Hilary K.; Ahmed, Nuzhat; Gadd, Geoffrey M.

    2005-01-01

    Cadmium resistance (0.1 to 1.0 mM) was studied in four pure and one mixed culture of sulfate-reducing bacteria (SRB). The growth of the bacteria was monitored with respect to carbon source (lactate) oxidation and sulfate reduction in the presence of various concentrations of cadmium chloride. Two strains Desulfovibrio desulfuricans DSM 1926 and Desulfococcus multivorans DSM 2059 showed the highest resistance to cadmium (0.5 mM). Transmission electron microscopy of the two strains showed intra...

  9. Cadmium immobilization by hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Smičiklas Ivana D.

    2003-01-01

    Full Text Available The contamination of air, soil and water by cadmium is a great environmental problem. If cadmium occurs in nature in ionic form, soluble in water, it easily enters into the food chain. Hydroxyapatite (HAP, Ca-o(POAe(OH2 is a sparingly soluble salt and an excellent matrix for the removal of heavy metals from solutions. Considerable research attention has been paid to the bond between Cc/2+ ions and synthetic hydroxyapatite of known composition. The sorption mechanism is complex. The dominant process is ion exchange, but surface adsorption, surface complexation and coprecipitation can also contribute to the overall mechanism. The sorption capacity depends on the characteristics of hydroxyapatite itself and on the experimental conditions. Under optimum conditions a maximum capacity of 0.8 mol Cd2+/mol HAP can be achieved. HAP is a potential sorbent for the remediation of contaminated water and soil, for industrial waste treatment, and it is also referenced as a material that can be used as a barrier around waste depositories.

  10. Role of melt behavior in modifying oxidation distribution using an interface incorporated model in selective laser melting of aluminum-based material

    Science.gov (United States)

    Gu, Dongdong; Dai, Donghua

    2016-08-01

    A transient three dimensional model for describing the molten pool dynamics and the response of oxidation film evolution in the selective laser melting of aluminum-based material is proposed. The physical difference in both sides of the scan track, powder-solid transformation and temperature dependent physical properties are taken into account. It shows that the heat energy tends to accumulate in the powder material rather than in the as-fabricated part, leading to the formation of the asymmetrical patterns of the temperature contour and the attendant larger dimensions of the molten pool in the powder phase. As a higher volumetric energy density is applied (≥1300 J/mm3), a severe evaporation is produced with the upward direction of velocity vector in the irradiated powder region while a restricted operating temperature is obtained in the as-fabricated part. The velocity vector continuously changes from upward direction to the downward one as the scan speed increases from 100 mm/s to 300 mm/s, promoting the generation of the debris of the oxidation films and the resultant homogeneous distribution state in the matrix. For the applied hatch spacing of 50 μm, a restricted remelting phenomenon of the as-fabricated part is produced with the upward direction of the convection flow, significantly reducing the turbulence of the thermal-capillary convection on the breaking of the oxidation films, and therefore, the connected oxidation films through the neighboring layers are typically formed. The morphology and distribution of the oxidation are experimentally acquired, which are in a good agreement with the results predicted by simulation.

  11. 镉真空蒸馏的热力学模型与过程%Thermodynamic Model and Experiment of Vacuum Distillation of Cadmium

    Institute of Scientific and Technical Information of China (English)

    王林军; 郭燕明; 桑文斌; 史伟民; 顾永明; 钱永彪; 闵嘉华; 吴汶海; 居建华; 夏义本

    2000-01-01

    In this paper, a novel approach for highly efficient purification of cadmium by vacuum distillation was reported. During the cadmium vacuum distillation, a small quantity of cadmium oxide film, produced under lower vacuum, was intentionally induced into the evaporator, and the presence of cadmium oxide changed the behavior of impurities. Meantime, a thermodynamic model of the process, which described the phase composition in the evaporator and condenser during evaporation of cadmium, was established. The model was used to classify the impurities according to their behavior in the purification process. On the base of the model, the purification of cadmium by one-stage and two-stage distillation and the validity of the model were also discussed.

  12. 镉真空蒸馏的热力学模型与过程%Thermodynamic Model and Experiment of Vacuum Distillation of Cadmium

    Institute of Scientific and Technical Information of China (English)

    王林军; 郭燕明; 桑文斌; 史伟民; 顾永明; 钱永彪; 闵嘉华; 吴汶海; 居建华; 夏义本

    2001-01-01

    In this paper, a novel approach for highly efficient purification of cadmium by vacuum distillation was reported. During the cadmium vacuum distillation, a small quantity of cadmium oxide film, produced under lower vacuum, was intentionally induced into the evaporator, and the presence of cadmium oxide changed the behavior of impurities. Meantime, a thermodynamic model of the process, which described the phase composition in the evaporator and condenser during evaporation of cadmium, was established. The model was used to classify the impurities according to their behavior in the purification process. On the base of the model, the purification of cadmium by one-stage and two-stage distillation and the validity of the model were also discussed.

  13. Arsenic(V) Incorporation in Vivianite during Microbial Reduction of Arsenic(V)-Bearing Biogenic Fe(III) (Oxyhydr)oxides.

    Science.gov (United States)

    Muehe, E Marie; Morin, Guillaume; Scheer, Lukas; Pape, Pierre Le; Esteve, Imène; Daus, Birgit; Kappler, Andreas

    2016-03-01

    The dissolution of arsenic-bearing iron(III) (oxyhydr)oxides during combined microbial iron(III) and arsenate(V) reduction is thought to be the main mechanism responsible for arsenic mobilization in reducing environments. Besides its mobilization during bioreduction, arsenic is often resequestered by newly forming secondary iron(II)-bearing mineral phases. In phosphate-bearing environments, iron(II) inputs generally lead to vivianite precipitation. In fact, in a previous study we observed that during bioreduction of arsenate(V)-bearing biogenic iron(III) (oxyhydr)oxides in phosphate-containing growth media, arsenate(V) was immobilized by the newly forming secondary iron(II) and iron(II)/iron(III)mineral phases, including vivianite. In the present study, changes in arsenic redox state and binding environment in these experiments were analyzed. We found that arsenate(V) partly replaced phosphate in vivianite, thus forming a vivianite-symplesite solid solution identified as Fe3(PO4)1.7(AsO4)0.3·8H2O. Our data suggests that in order to predict the fate of arsenic during the bioreduction of abiogenic and biogenic iron(III) (oxyhydr)oxides in arsenic-contaminated environments, the formation of symplesite-vivianite minerals needs to be considered. Indeed, such mineral phases could contribute to a delayed and slow release of arsenic in phosphate-bearing surface and groundwater environments.

  14. Memory window engineering of Ta2O5‑x oxide-based resistive switches via incorporation of various insulating frames

    Science.gov (United States)

    Lee, Ah Rahm; Baek, Gwang Ho; Kim, Tae Yoon; Ko, Won Bae; Yang, Seung Mo; Kim, Jongmin; Im, Hyun Sik; Hong, Jin Pyo

    2016-07-01

    Three-dimensional (3D) stackable memory frames, including nano-scaled crossbar arrays, are one of the most reliable building blocks to meet the demand of high-density non-volatile memory electronics. However, their utilization has the disadvantage of introducing issues related to sneak paths, which can negatively impact device performance. We address the enhancement of complementary resistive switching (CRS) features via the incorporation of insulating frames as a generic approach to extend their use; here, a Pt/Ta2O5‑x/Ta/Ta2O5‑x/Pt frame is chosen as the basic CRS cell. The incorporation of Ta/Ta2O5‑x/Ta or Pt/amorphous TaN/Pt insulting frames into the basic CRS cell ensures the appreciably advanced memory features of CRS cells including higher on/off ratios, improved read margins, and increased selectivity without reliability degradation. Experimental observations identified that a suitable insulating frame is crucial for adjusting the abrupt reset events of the switching element, thereby facilitating the enhanced electrical characteristics of CRS cells that are suitable for practical applications.

  15. Cadmium(2) complexes of cytosine

    International Nuclear Information System (INIS)

    Complexes of cadmium(2) with cytosine obtained from aqueous or physiological solutions at room temperature are reported. The complexes were characterized by spectroscopic, conductometric, 1H-NMR, and 13C-NMR measurements and also by thermogravimetry. (Authors)

  16. Discovery of the Cadmium Isotopes

    OpenAIRE

    Amos, S.; Thoennessen, M

    2009-01-01

    Thirty-seven cadmium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Cadmium telluride nuclear radiation detectors

    International Nuclear Information System (INIS)

    The characteristics and performance of undoped high resistivity cadmium telluride detectors are compared to chlorine lifted counters. It is shown, in particular, that Undodep CdTe is in fact aluminium doped and that compensation occurs, as an silicon or germanium, by pair and triplet formation between the group III donor and the doubly charged cadmium vacancy acceptor. Furthermore, in chlorine doped samples, the polarization effect results from the unpaired level at Esub(c)-0,6eV

  18. Carbon Dioxide, Methane, and Nitrous Oxide Emissions from a Rice-Wheat Rotation as Affected by Crop Residue Incorporation and Temperature

    Institute of Scientific and Technical Information of China (English)

    邹建文; 黄耀; 宗良纲; 郑循华; 王跃思

    2004-01-01

    Field measurements were made from June 2001 to May 2002 to evaluate the effect of crop residue application and temperature on CO2, CH4, and N2O emissions within an entire rice-wheat rotation season.Rapeseed cake and wheat straw were incorporated into the soil at a rate of 2.25 t hm-2 when the rice crop was transplanted in June 2001. Compared with the control, the incorporation of rapeseed cake enhanced the emissions of CO2, CH4, and N2O in the rice-growing season by 12.3%, 252.3%, and 17.5%,respectively, while no further effect was held on the emissions of CO2 and N2O in the following wheatgrowing season. The incorporation of wheat straw enhanced the emissions of CO2 and CH4 by 7.1%and 249.6%, respectively, but reduced the N2O emission by 18.8% in the rice-growing season. Significant reductions of 17.8% for the CO2 and of 12.9% for the N2O emission were observed in the following wheatgrowing season. A positive correlation existed between the emissions of N2O and CO2 (R2 = 0.445, n =73, p < 0.001) from the rice-growing season when N2O was emitted. A trade-off relationship between the emissions of CH4 and N2O was found in the rice-growing season. The CH4 emission was significantly correlated with the CO2 emission for the period from rice transplantation to field drainage, but not for the entire rice-growing season. In addition, air temperature was found to regulate the CO2 emissions from the non-waterlogged period over the entire rice-wheat rotation season and the N2O emissions from the nonwaterlogged period of the rice-growing season, which can be quantitatively described by an exponential function. The temperature coefficient (Q10) was then evaluated to be 2.3±0.2 for the CO2 emission and 3.9±0.4 for the N2O emission, respectively.

  19. Speciation of Dissolved Cadmium

    DEFF Research Database (Denmark)

    Holm, Peter Engelund; Andersen, Sjur; Christensen, Thomas Højlund

    1995-01-01

    ) method separates dissolved Cd into free divalent Cd (Cd 2+) and complexed Cd and furthermore separates the latter into the operationally defined forms: labile, slowly labile and stable complexes. The dialysis (ED) method determines high molecular weight Cd complexes (above 1000mol. wt). For both methods...... the reproducibility was good. By combining the results of the GEOCHEM calculations in terms of the inorganic complexes, and the IE results, the fractions of free and inorganically complexed Cd were estimated. The IE and ED results furthermore provided information about the organic complexes. Selected environmental......Equilibrium dialysis and ion exchange methods, as well as computer calculations (GEOCHEM), were applied for speciation of dissolved cadmium (Cd) in test solutions and leachate samples. The leachate samples originated from soil, compost, landfill waste and industrial waste. The ion exchange (IE...

  20. Incorporating Amino Acid Esters into Catalysts for Hydrogen Oxidation: Steric and Electronic Effects and the Role of Water as a Base

    Energy Technology Data Exchange (ETDEWEB)

    Lense, Sheri; Ho, Ming-Hsun; Chen, Shentan; Jain, Avijita; Raugei, Simone; Linehan, John C.; Roberts, John A. S.; Appel, Aaron M.; Shaw, Wendy

    2012-10-08

    Four derivatives of a hydrogen oxidation catalyst, [Ni(PCy2NBn-R2)2]2+ (Cy = cyclohexyl, Bn = benzyl, R = OMe, COOMe, CO-alanine-methyl ester, CO-phenylalanine-methyl ester), have been prepared to investigate steric and electronic effects on catalysis. Each complex was characterized spectroscopically and electrochemically, and thermodynamic data were determined. Crystal structures are also reported for the -OMe and -COOMe derivatives. All four catalysts were found to be active for H2 oxidation. The methyl ester (R = COOMe) and amino acid ester containing complexes (R = CO-alanine-methyl ester or CO-phenylalanine-methyl ester) had rates slower (4 s–1) than that of the parent complex (10 s–1), in which R = H, which is consistent with the lower amine pKa's and less favorable ΔGH2's found for these electron-withdrawing substituents. Dynamic processes for the amino acid ester containing complexes were also investigated and found not to hinder catalysis. The electron-donating methyl ether derivative (R = OMe) was prepared to compare electronic effects and has a catalytic rate similar to that of the parent complex. In the course of these studies, it was found that water could act as a weak base for H2 oxidation, although catalytic turnover requires a higher potential and utilizes a different sequence of catalytic steps than when using a base with a higher pKa. Finally and importantly, these catalysts provide a foundation upon which larger peptides can be attached to [Ni(PCy2NBn2)2]2+ hydrogen oxidation catalysts in order to more fully investigate and implement the effects of the outer coordination sphere.

  1. A facile solution combustion synthesis of nanosized amorphous iron oxide incorporated in a carbon matrix for use as a high-performance lithium ion battery anode material

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chunyu, E-mail: chunyu6zhu@gmail.com; Saito, Genki; Akiyama, Tomohiro

    2015-06-05

    Highlights: • Iron oxide–carbon composite was fabricated by facile solution combustion synthesis. • Iron oxide nanoparticles of about 5 nm were uniformly embedded in dense carbon matrix. • The composite exhibited enhanced cyclability and rate capability. • A high capacity of 687 mA h g{sup −1} after 200 cycles at a current rate of 0.5 A g{sup −1} were obtained. - Abstract: An amorphous iron oxide–carbon composite has been fabricated through an effective, inexpensive, and scalable method employing solution combustion synthesis. Amorphous iron oxide nanoparticles with diameters of about 5 nm were synthesized and uniformly embedded in a dense carbon matrix. The synthesized composite exhibits enhanced cyclability and rate capability, showing a high reversible capacity of 687 mA h g{sup −1} after 200 discharge/charge cycles at a current rate of 0.5 A g{sup −1}, compared to the 400 mA h g{sup −1} observed for Fe{sub 2}O{sub 3} nanoparticles. This enhanced performance was retained despite more demanding conditions, delivering a high capacity of about 525 mA h g{sup −1} and a nearly perfect coulombic efficiency even after 400 cycles at 1 A g{sup −1}. The easy production and superior electrochemical properties of this composite suggest that it is a promising material for use as an anode material in high performance lithium ion batteries.

  2. Bioremediation of adverse impact of cadmium toxicity on Cassia italica Mill by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Hashem, Abeer; Abd Allah, E F; Alqarawi, A A; Egamberdieva, Dilfuza

    2016-01-01

    Cassia italica Mill is an important medicinal plant within the family Fabaceae. Pot experiment was conducted to evaluate cadmium stress induced changes in physiological and biochemical attributes in C. italica with and without arbuscular mycorrhizal fungi (AMF). Cadmium stressed plant showed reduced chlorophyll pigment and protein content while AMF inoculation enhanced the chlorophyll and protein content considerably. AMF also ameliorated the cadmium stress induced reduction in total chlorophyll and protein contents by 19.30% and 38.29%, respectively. Cadmium stress enhanced lipid peroxidation while AMF inoculation reduced lipid peroxidation considerably. Increase in proline and phenol content was observed due to cadmium stress and AMF inoculation caused a further increase in proline and phenol content ensuring better growth under stressed conditions. AMF alone also enhanced proline and phenol content. Activity of antioxidant enzymes enhanced under cadmium treatment and AMF inoculation further enhanced their activity thereby strengthening the antioxidant system. Enhanced activities of antioxidants and increased accumulation of osmolytes help plants to avoid damaging impact of oxidative damage. The research has shown that AMF inoculation mitigated the negative impact of stress by reducing the lipid peroxidation and enhancing the antioxidant activity. The present study strongly supports employing AMF as the biological mean for enhancing the cadmium stress tolerance of C. italica. PMID:26858537

  3. Cadmium minimization in wheat: A critical review.

    Science.gov (United States)

    Rizwan, Muhammad; Ali, Shafaqat; Abbas, Tahir; Zia-Ur-Rehman, Muhammad; Hannan, Fakhir; Keller, Catherine; Al-Wabel, Mohammad I; Ok, Yong Sik

    2016-08-01

    Cadmium (Cd) accumulation in wheat (Triticum aestivum L.) and its subsequent transfer to food chain is a major environmental issue worldwide. Understanding wheat response to Cd stress and its management for aiming to reduce Cd uptake and accumulation in wheat may help to improve wheat growth and grain quality. This paper reviewed the toxic effects, tolerance mechanisms, and management of Cd stress in wheat. It was concluded that Cd decreased germination, growth, mineral nutrients, photosynthesis and grain yield of wheat and plant response to Cd toxicity varies with cultivars, growth conditions and duration of stress applied. Cadmium caused oxidative stress and genotoxicity in wheat plants. Stimulation of antioxidant defense system, osmoregulation, ion homeostasis and over production of signalling molecules are important adaptive strategies of wheat under Cd stress. Exogenous application of plant growth regulators, inorganic amendments, proper fertilization, silicon, and organic, manures and biochar, amendments are commonly used for the reduction of Cd uptake in wheat. Selection of low Cd-accumulating wheat cultivars, crop rotation, soil type, and exogenous application of microbes are among the other agronomic practices successfully employed in reducing Cd uptake by wheat. These management practices could enhance wheat tolerance to Cd stress and reduce the transfer of Cd to the food chain. However, their long-term sustainability in reducing Cd uptake by wheat needs further assessment.

  4. Cadmium minimization in wheat: A critical review.

    Science.gov (United States)

    Rizwan, Muhammad; Ali, Shafaqat; Abbas, Tahir; Zia-Ur-Rehman, Muhammad; Hannan, Fakhir; Keller, Catherine; Al-Wabel, Mohammad I; Ok, Yong Sik

    2016-08-01

    Cadmium (Cd) accumulation in wheat (Triticum aestivum L.) and its subsequent transfer to food chain is a major environmental issue worldwide. Understanding wheat response to Cd stress and its management for aiming to reduce Cd uptake and accumulation in wheat may help to improve wheat growth and grain quality. This paper reviewed the toxic effects, tolerance mechanisms, and management of Cd stress in wheat. It was concluded that Cd decreased germination, growth, mineral nutrients, photosynthesis and grain yield of wheat and plant response to Cd toxicity varies with cultivars, growth conditions and duration of stress applied. Cadmium caused oxidative stress and genotoxicity in wheat plants. Stimulation of antioxidant defense system, osmoregulation, ion homeostasis and over production of signalling molecules are important adaptive strategies of wheat under Cd stress. Exogenous application of plant growth regulators, inorganic amendments, proper fertilization, silicon, and organic, manures and biochar, amendments are commonly used for the reduction of Cd uptake in wheat. Selection of low Cd-accumulating wheat cultivars, crop rotation, soil type, and exogenous application of microbes are among the other agronomic practices successfully employed in reducing Cd uptake by wheat. These management practices could enhance wheat tolerance to Cd stress and reduce the transfer of Cd to the food chain. However, their long-term sustainability in reducing Cd uptake by wheat needs further assessment. PMID:27062345

  5. 葡萄籽油对镉致大鼠肝脏细胞氧化损伤的保护作用%Protective Effects of Grape Seed Oil on Oxidative Damage in Rat Liver Cells Exposed to Cadmium

    Institute of Scientific and Technical Information of China (English)

    邹志辉; 杨翠婵; 李伯灵

    2011-01-01

    [ Objective ] To explore the protective effect of grape seed oil (GSO) on DNA oxidative damage of liver cells in rats exposed to CdCl2. [ Methods ] A total of 40 SD rats of SPF grade were randomly divided into 5 groups, which were the control group (intraperitoneal injection and gastric perfusion of normal saline with same volume), the CdCl2 exposure-positive group (intraperitoneal injection of l.0mg/kg CdCl2 and gastric perfusion of normal saline with the same volume), and the GSO low-, medium- and high-dose intervention groups (intraperitoneal injection of l.0mg/kg CdCl2 and gastric perfusion of 0.66mg/kg, 1.32mg/kg, 2.64mg/kg GSO, respectively) with 8 of either gender in each group. Malondialdehyde (MDA) content in liver was measured by thiobarbituric acid (TBA) method. DNA oxidative damage was measured by single cell gel eletrophoresis (SCGE). [ Results ] The l.0mg/kg CdCl2 induced a significant increase in MDA content and DNA oxidative damage. The difference of MDA contents between the GSO high-dose intervention group and the CdCl2 exposure-positive group was significant (P< 0.05). The clearances in the GSO low-, medium- and high-dose intervention groups were 54.55%, 54.55% and 100.00%, respectively. The DNA damage significantly decreased in the GSO intervention groups in a dose-dependent manner, compared with the CdCl2 exposure-positive group (P<0.05). [ Conclusion ] A certain dose of grape seed oil can induce a decrease in MDA content and DNA damage in rat liver after cadmium exposure.%[目的]探讨葡萄籽油(grape seed oil,GSO)对氯化镉(CdCl2)诱导大鼠肝脏细胞DNA损伤的保护作用.[方法]将40只SPF级雌雄各半SD大鼠随机分为对照组(腹腔注射生理盐水和灌胃生理盐水)、染镉组(腹腔注射1.0 mg/kg的CdCl2和灌胃生理盐水)、GSO低、中、高剂量干预组(均腹腔注射1.0 mg/kg CdC12,同时分别灌胃0.66、1.32、2.64 mg/kgGSO),硫代巴比妥酸法检测肝中丙二醛(malondialdehyde,MDA)的含量,采

  6. Incorporation of {sup 13}C-labeled intermediates into developing lignin revealed by analytical pyrolysis and CuO oxidation in combination with IRM-GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Eglinton, T.I.; Goni, M.A. [Woods Hole Oceanographic Institution, MA (United States); Boon, J.J. [FOM Institute, Amsterdam (Netherlands)] [and others

    1995-12-31

    Tissue samples from Ginkgo shoots (Ginkgo biloba L.) and Rice grass (Oryzasitiva sp.) incubated in the presence of {sup 13}C-labeled substrates such as coniferin (postulated to be biosynthetic intermediates in lignin biosynthesis) were studied using thermal and chemical dissociation methods in combination with molecular-level isotopic measurements. The aim of the study was (1) to investigate dissociation mechanisms, and (2) to examine and quantify the proportions of labeled material incorporated within each sample. Isotopic analysis of specific dissociation products revealed the presence of the label in its original positions, and only within lignin-derived (phenolic) products. Moreover, the distribution and isotopic composition of the dissociation products strongly suggest an origin from newly-formed lignin. These results clearly indicate that there is no {open_quotes}scrambling{close_quotes} of carbon atoms as a result of the dissociation process, thereby lending support to this analytical approach. In addition, the data provide confidence in the selective labeling approach for elucidation of the structure and biosynthesis of lignin.

  7. Electrical properties of Ge metal-oxide-semiconductor capacitors with high-k La2O3 gate dielectric incorporated by N or/and Ti

    Science.gov (United States)

    Huoxi, Xu; Jingping, Xu

    2016-06-01

    LaON, LaTiO and LaTiON films are deposited as gate dielectrics by incorporating N or/and Ti into La2O3 using the sputtering method to fabricate Ge MOS capacitors, and the electrical properties of the devices are carefully examined. LaON/Ge capacitors exhibit the best interface quality, gate leakage property and device reliability, but a smaller k value (14.9). LaTiO/Ge capacitors exhibit a higher k value (22.7), but a deteriorated interface quality, gate leakage property and device reliability. LaTiON/Ge capacitors exhibit the highest k value (24.6), and a relatively better interface quality (3.1 × 1011 eV-1 cm-2), gate leakage property (3.6 × 10-3 A/cm2 at V g = 1 V + V fb) and device reliability. Therefore, LaTiON is more suitable for high performance Ge MOS devices as a gate dielectric than LaON and LaTiO materials. Project supported by the National Natural Science Foundation of China (No. 61274112), the Natural Science Foundation of Hubei Province (No. 2011CDB165), and the Scientific Research Program of Huanggang Normal University (No. 2012028803).

  8. Molecular Mechanisms of Malignant Transformation by Low Dose Cadmium in Normal Human Bronchial Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Laura Cartularo

    Full Text Available Cadmium is a carcinogenic metal, the mechanisms of which are not fully understood. In this study, human bronchial epithelial cells were transformed with sub-toxic doses of cadmium (0.01, 0.05, and 0.1 μM and transformed clones were characterized for gene expression changes using RNA-seq, as well as other molecular measurements. 440 genes were upregulated and 47 genes were downregulated in cadmium clones relative to control clones over 1.25-fold. Upregulated genes were associated mostly with gene ontology terms related to embryonic development, immune response, and cell movement, while downregulated genes were associated with RNA metabolism and regulation of transcription. Several embryonic genes were upregulated, including the transcription regulator SATB2. SATB2 is critical for normal skeletal development and has roles in gene expression regulation and chromatin remodeling. Small hairpin RNA knockdown of SATB2 significantly inhibited growth in soft agar, indicating its potential as a driver of metal-induced carcinogenesis. An increase in oxidative stress and autophagy was observed in cadmium clones. In addition, the DNA repair protein O6-methylguanine-DNA-methyltransferase was depleted by transformation with cadmium. MGMT loss caused significant decrease in cell viability after treatment with the alkylating agent temozolomide, demonstrating diminished capacity to repair such damage. Results reveal various mechanisms of cadmium-induced malignant transformation in BEAS-2B cells including upregulation of SATB2, downregulation of MGMT, and increased oxidative stress.

  9. Cadmium Induced Changes in Metabolic Function of Mitochondrial Isolated from Potato Tissue (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Chagra Ali

    2009-01-01

    Full Text Available Problem statement: Cadmium is highly toxic at low concentrations, but the mechanism of its toxicity is still not understood particularly at the cellular and subcellular level. Approach: In this study we examined the effects of cadmium on the oxidophosphorylation properties of mitochondria isolated from potatoes. Results: Cadmium strongly disturbed the respiratory metabolism of mitochondria isolated especially in the transfer of electrons by cyanide pathway. Meanwhile, cadmium altered the composition of lipid fatty acids polar while inhibiting catalase activity, a key enzyme in the detoxification (antioxidant process. In addition, cadmium caused an increase in mitochondrial volume associated with strong inhibition of ATPase activity, which could be explained by a transport of the potassium ion stimulation at the origin of the massive influx of H+ by antiport through the K+/H+ leading to a decoupling (cut of mitochondrial oxidative phosphorylation. The swelling of mitochondria was accompanied by the rupture of the mitochondrial outer membrane and thus the release of Cytochrome C, which appears to be the initial phase of apoptosis. Conclusion: Following this study, it appeared that cadmium generates in potato the isolated mitochondria a concentration-dependent oxidative stress.

  10. The effect of cadmium on the growth and antioxidant response for freshwater algae Chlorella vulgaris.

    Science.gov (United States)

    Cheng, Jinfeng; Qiu, Hongchen; Chang, Zhaoyang; Jiang, Zaimin; Yin, Wenke

    2016-01-01

    The objective of the present work was to evaluate the effect of exogenously applied cadmium on the physiological response of green algae Chlorella vulgaris. The study investigated the long-term effect (18 days) of cadmium on the levels of algae biomass, assimilation pigment composition, soluble protein, oxidative status (production of hydrogen peroxide and superoxide anion), antioxidant enzymes (such as superoxide dismutase, peroxidase, catalase and glutathione reductase enzyme) in C. vulgaris. The results showed that growth, the amount of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids gradually decreased with increasing cadmium over 18 days exposure. Cadmium at concentration of 7 mg L(-1) inhibited algal growth expressed as the number of cells. Our research found that C. vulgaris has a high tolerance to cadmium. Contents of chlorophylls (Chl a and Chl b) and carotenoids (Car) of C. vulgaris was significantly decline with rising concentration of cadmium (p alga with exposure to Cd(II) seemed to be parameters as biomarkers for metal-induced oxidative stress. PMID:27652004

  11. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells

    Energy Technology Data Exchange (ETDEWEB)

    Person, Rachel J.; Tokar, Erik J.; Xu, Yuanyuan; Orihuela, Ruben; Ngalame, Ntube N. Olive; Waalkes, Michael P., E-mail: waalkes@niehs.nih.gov

    2013-12-01

    Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 μM cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. - Highlights: • Chronic cadmium exposure induces cancer cell characteristics in human lung cells. • This provides an in vitro model of cadmium-induced human lung cell transformation. • This occurred with general and lung specific changes typical for cancer cells. • These findings add insight to the

  12. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells

    International Nuclear Information System (INIS)

    Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 μM cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. - Highlights: • Chronic cadmium exposure induces cancer cell characteristics in human lung cells. • This provides an in vitro model of cadmium-induced human lung cell transformation. • This occurred with general and lung specific changes typical for cancer cells. • These findings add insight to the relationship

  13. Zinc-induced protection against cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Early, J.L.; Schnell, R.C.

    1978-02-01

    Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

  14. Li2S@C composite incorporated into 3D reduced graphene oxide as a cathode material for lithium-sulfur batteries

    Science.gov (United States)

    Wang, D. H.; Xie, D.; Yang, T.; Zhong, Y.; Wang, X. L.; Xia, X. H.; Gu, C. D.; Tu, J. P.

    2016-05-01

    Surface conductive engineering on Li2S is critical for construction of advanced cathodes of lithium-sulfur batteries. Herein, we construct a high-performance Li2S-based composite cathode with the help of three-dimensional reduced graphene oxide (3D-rGO) network and outer carbon coating. Typically, the Li2S@C particles are uniformly embedded into 3D-rGO to form a binder-free 3D-rGO-Li2S@C cathode by the combination of a liquid solution-evaporation coating and PVP (Polyvinyl Pyrrolidone) carbonization. The 3D-rGO-Li2S@C cathode exhibits a high initial discharge capacity of 856 mAh g-1 at 0.1C, superior cycling stability with a capacity of 388.4 mAh g-1 after 200 cycles at 1C, corresponding to a low capacity fading rate. It is demonstrated that the outer conductive coating is effective and necessary for electrochemical enhancement of Li2S cathodes by improving electrical conductivity and prohibiting polysulfide from shuttling during cycling.

  15. Chemical and microstructural study in radio frequency sputtered CdTe oxide films prepared at different N{sub 2}O pressures. Oxygen incorporation and film resputtering

    Energy Technology Data Exchange (ETDEWEB)

    Caballero-Briones, F. [CICATA-IPN Unidad Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, 89600, Altamira, Tamps (Mexico)], E-mail: fcaballerobriones@ub.edu; Oliva, A.I.; Bartolo-Perez, P. [Applied Physics Department, CINVESTAV-IPN Unidad Merida, A.P. 73 Cordemex, 97310 Merida, Yucatan (Mexico); Zapata-Navarro, A. [CICATA-IPN Unidad Legaria, Legaria 694 Col. Irrigacion 11500, Mexico, D.F. (Mexico); Pena, J.L. [Applied Physics Department, CINVESTAV-IPN Unidad Merida, A.P. 73 Cordemex, 97310 Merida, Yucatan (Mexico)

    2008-10-01

    CdTe oxide films were grown by radio frequency sputtering in Ar-N{sub 2}O plasma at different N{sub 2}O partial pressures. The film oxygen content determined by Auger electron spectroscopy ranged from 15 to 60 at.%. The free O{sub 2} production during film deposition was monitored by in situ mass spectroscopy and it was found that it increases linearly over a critical N{sub 2}O pressure {approx} 4.7 x 10{sup -3} Pa alike the oxygen in the films. Film microstructure was studied by Raman spectroscopy and atomic force microscopy. Evidence of bands related to terminal Te-O vibrations was found in films prepared below the N{sub 2}O critical pressure, becoming predominant in films with higher oxygen content. The morphology and roughness evolution of the films confirm that they consist of a mixture of phases. Surface structures of the Ia-type and of the Ib-type were observed below and above the critical N{sub 2}O pressure. Eventually, ion bombardment process caused film resputtering.

  16. Chemical and microstructural study in radio frequency sputtered CdTe oxide films prepared at different N2O pressures. Oxygen incorporation and film resputtering

    International Nuclear Information System (INIS)

    CdTe oxide films were grown by radio frequency sputtering in Ar-N2O plasma at different N2O partial pressures. The film oxygen content determined by Auger electron spectroscopy ranged from 15 to 60 at.%. The free O2 production during film deposition was monitored by in situ mass spectroscopy and it was found that it increases linearly over a critical N2O pressure ∼ 4.7 x 10-3 Pa alike the oxygen in the films. Film microstructure was studied by Raman spectroscopy and atomic force microscopy. Evidence of bands related to terminal Te-O vibrations was found in films prepared below the N2O critical pressure, becoming predominant in films with higher oxygen content. The morphology and roughness evolution of the films confirm that they consist of a mixture of phases. Surface structures of the Ia-type and of the Ib-type were observed below and above the critical N2O pressure. Eventually, ion bombardment process caused film resputtering

  17. Bioavailability of cadmium from linseed and cocoa

    DEFF Research Database (Denmark)

    Hansen, Max; Sloth, Jens Jørgen; Rasmussen, Rie Romme

    In Denmark and EU the exposure of cadmium from food is at a level that is relatively close to the Tolerable Daily Intake (TDI). This report describes an investigation of the bioavailability of cadmium in selected food items known to contain high levels of cadmium. The purpose was to provide data ...... or crushed linseed nor the intake of cocoa and chocolate....

  18. Magnetic field can alleviate toxicological effect induced by cadmium in mungbean seedlings.

    Science.gov (United States)

    Chen, Yi-ping; Li, Ran; He, Jun-Min

    2011-06-01

    To alleviate toxicological effect induced by cadmium in mungbean seedlings, seeds were divided into four groups: The controls groups (CK, without treatment), magnetic field treated groups (MF), cadmium treated groups (CS), and magnetic field treated followed by cadmium treated groups (MF + CS).The results showed: (i) Compared with the controls, cadmium stress resulted in enhancing in the concentration of malondialdehyde, H(2)O(2) and O(2-), and the conductivity of electrolyte leakage while decreasing in the nitrice oxide synthase (NOS) activity, the concentration of nitrice oxide (NO), chlorophyll and total carbon and nitrogen, the net photosynthetic rate, the stomatal conductance, the transpiration rate, the water use efficiency, the lateral number and seedlings growth except for intercellular CO(2) concentration increase. However, the seedlings treated with 600 mT magnetic field followed by cadmium stress the concentration of malondialdehyde, H(2)O(2) and O(2-), and the conductivity of electrolyte leakage decreased, while the above mentioned NO concentration, NOS activity, photosynthesis and growth parameters increased compared to cadmium stress alone. (ii) Compared with the cadmium stress (CS), the seedling growth were inhibited when the seeds were treated with NO scavenger (hemoglobin, HB) and inhibition of NO generating enzyme (sodium tungstate, ST), conversely, the seedling growth were improved by the NO donor sodium nitroprusside (SNP) and CaCl(2). In the case of the HB and ST treatment followed by magnetic field and then the seedling subjected to CS, the seedlings growth was better than that of hemoglobin (HB) followed by CS and ST followed by CS. The seeds were treated with SNP and CaCl(2) followed by MF, and then subjected to CS, the seedlings growth were better than that of SNP followed by CS, and CaCl(2) followed by CS. These results suggested that magnetic field compensates for the toxicological effects of cadmium exposure are related to NO signal.

  19. mRNA expression of a cadmium-responsive gene is a sensitive biomarker of cadmium exposure in the soil collembolan Folsomia candida

    Energy Technology Data Exchange (ETDEWEB)

    Nakamori, Taizo, E-mail: taizo@ynu.ac.j [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Fujimori, Akira [Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kinoshita, Keiji [Nagoya University Avian Bioscience Research Centre, Graduate School of Bioagricultural Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Ban-nai, Tadaaki; Kubota, Yoshihisa; Yoshida, Satoshi [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2010-05-15

    The gene expression of environmental organisms is useful as a biomarker of environmental pollution. One of its advantages is high sensitivity. We identified the cDNA of a novel cadmium-responsive gene in the soil collembolan Folsomia candida. The deduced protein, designated 'metallothionein-like motif containing protein' (MTC), was cysteine-rich and contained a metallothionein-like motif with similarity to metallothionein, but had a much longer sequence than metallothionein and contained repeated sequences of amino acids. Expression of MTC mRNA was sensitively induced by cadmium exposure at 0.3 mg/kg of dry food, a concentration at which toxic effects are not observed, but expression was not affected by gamma-ray exposure (an inducer of oxidative stress). These findings suggest that MTC is involved in cadmium-binding processes rather than in oxidative-stress responses. In conclusion, we suggest that gene expression of MTC may be a candidate biomarker for detecting low levels of cadmium contamination in soil. - The mRNA expression of a gene potentially encoding a metallothionein-like motif containing protein is sensitively induced by cadmium exposure in the soil collembolan Folsomia candida.

  20. Surface Passivation of Mercury-Cadmium-Telluride Infrared Detectors

    Directory of Open Access Journals (Sweden)

    R. Singh

    1991-07-01

    Full Text Available The theoretical considerations and practical aspects of passivating insulator films, in the context of their use on high-performance mercury cadmium telluride (MCT infrared detectors are reviewed. The methods of growth, the interface properties and the applications of both native and deposited passivant films have been discussed. Native films include anodic, chemical, photochemical, and plasma oxides as well as anodic sulphides and fluoro-oxides. Deposited films include ZnS, photo-CVD-grown SiO2, CDTe, and SiN/sub x/. The properties of all these passivant films on MCT have been summarized.

  1. Monitoring of population shifts in an enriched nitrifying system under gradually increased cadmium loading

    Energy Technology Data Exchange (ETDEWEB)

    Mertoglu, Bulent [Department of Bioengineering, Marmara University, 34722 Goztepe, Istanbul (Turkey)], E-mail: bmertoglu@eng.marmara.edu.tr; Semerci, Neslihan [Department of Environmental Engineering, Marmara University, 34722 Goztepe, Istanbul (Turkey); Guler, Nuray [TUBITAK-Marmara Research Center, Chemistry and Environmental Institute, 41470 Gebze, Kocaeli (Turkey); Calli, Baris [Department of Environmental Engineering, Marmara University, 34722 Goztepe, Istanbul (Turkey); Cecen, Ferhan [Institute of Environmental Sciences, Bogazici University, Bebek, Istanbul (Turkey); Saatci, Ahmet Mete [Department of Environmental Engineering, Marmara University, 34722 Goztepe, Istanbul (Turkey)

    2008-12-30

    The changes in nitrifying bacterial population under cadmium loading were monitored and evaluated in a laboratory scale continuous-flow enriched nitrification system. For this purpose, the following molecular microbiological methods were used: slot-blot hybridization, denaturing gradient gel electrophoresis (DGGE), real-time PCR followed by melting curve analysis, cloning and sequence analysis. The initial cadmium concentration was incrementally increased from 1 to 10 mg/l which led to a drop in ammonia removal efficiency from 99 to 10%. Inhibition was recovered when cadmium loading was stopped. During the second application of cadmium, nitrifying population became more tolerant. Even at 15 mg/l Cd, only a minor inhibition was observed. To investigate the variations in ammonia and nitrite oxidizing bacteria populations in a period of 483 days, ammonia monooxygenase (amoA) and 16S rRNA genes-based molecular techniques were used. An obvious shift was experienced in the diversity of ammonia oxidizers after the first application of 10 mg/l Cd. Metal-tolerant ammonia oxidizing species became dominant and the microbial diversity sharply shifted from Nitrosomonas and Nitrosococcus sp. to Nitrosospira sp. which were observed to tolerate higher cadmium loadings. This result indicated that the extent of nitrification inhibition was not only related to the metal concentration and quantity of microorganisms but also depended on the type of species.

  2. Oral cadmium chloride intoxication in mice

    DEFF Research Database (Denmark)

    Andersen, O; Nielsen, J B; Svendsen, P

    1988-01-01

    Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effect....... Thus, orally administered DDC enhanced cadmium-induced duodenal and ileal tissue damage and inhibition of peristalsis, as indicated by an increased intestinal transit time. At low cadmium doses, the whole-body retention of cadmium was increased by oral DDC administration. Intraperitoneally administered...

  3. Preparation and Hemocompatibility of Neodymium Incorporated Zinc Oxide Thin Films%钕掺杂ZnO薄膜的制备及抗凝血性能研究

    Institute of Scientific and Technical Information of China (English)

    黄展云; 罗平; 陈弟虎

    2011-01-01

    采用射频磁控溅射方法在硅(100)衬底上制备了不同含量元素钕(Nd)掺杂的氧化锌薄膜.XRD分析表明,所有ZnO薄膜都具有c轴择优取向.随着Nd掺杂量的增加,(002)衍射峰的强度减弱,颗粒的尺寸变小.紫外-可见光谱分析表明,所有薄膜在可见光区的透过率超过85%,随着Nd掺杂量的增加,光学带隙从3.30 eV增加到3.40 eV.用XPS对薄膜的表面化学态进行表征,Nd元素在ZnO薄膜表面以Nd3+离子态存在.用接触角测试薄膜表面的浸润性,并计算其表面能.用血小板粘附实验研究不同含量Nd掺杂ZnO薄膜的血液相容性,其结果表明稀土钕掺杂后血小板的粘附数量和形变都较少,稀土掺杂和疏水性的提高是改善氧化锌薄膜抗凝血性能的主要原因.%Zinc oxide thin films doped with different neodymium (Nd) contents (1at%, 2at% and 3at%) were grown on Si (100) substrates by radio frequency magnetron sputtering. X-ray diffraction (XRD) patterns show that all of the ZnO thin films have highly preferred growth along c-axis direction. The intensity of (002) diffraction peaks weakens and the gain size decreases with the increasing of Nd dopants. The optical transmittance of all the films exceeds 85% in the visible light region, and the optical band gap increases from 3.30 eV to 3.40 eV with the increasing of the Nd dopants. The surface chemical state of ZnO thin films is examined by X-ray photoelectron spectroscope (XPS), confirming that Nd element exists as Nd3+ in the films. Contact angle test is also employed to analyze the effect of Nd dopant on the wettability and surface energy. The platelets adhesion experiment shows that fewer platelets adhere and deform on ZnO and Nd doped ZnO thin films. Nd element and hydrophobility surface are the main factors leading to the better blood compatibility of ZnO thin films.

  4. Incorporation of noble metals into aerogels

    Science.gov (United States)

    Hair, Lucy M.; Sanner, Robert D.; Coronado, Paul R.

    1998-01-01

    Aerogels or xerogels containing atomically dispersed noble metals for applications such environmental remediation. New noble metal precursors, such as Pt--Si or Pd(Si--P).sub.2, have been created to bridge the incompatibility between noble metals and oxygen, followed by their incorporation into the aerogel or xerogel through sol-gel chemistry and processing. Applications include oxidation of hydrocarbons and reduction of nitrogen oxide species, complete oxidation of volatile organic carbon species, oxidative membranes for photocatalysis and partial oxidation for synthetic applications.

  5. 2D X-ray and FTIR micro-analysis of the degradation of cadmium yellow pigment in paintings of Henri Matisse

    Science.gov (United States)

    Pouyet, E.; Cotte, M.; Fayard, B.; Salomé, M.; Meirer, F.; Mehta, A.; Uffelman, E. S.; Hull, A.; Vanmeert, F.; Kieffer, J.; Burghammer, M.; Janssens, K.; Sette, F.; Mass, J.

    2015-11-01

    The chemical and physical alterations of cadmium yellow (CdS) paints in Henri Matisse's The Joy of Life (1905-1906, The Barnes Foundation) have been recognized since 2006, when a survey by portable X-ray fluorescence identified this pigment in all altered regions of the monumental painting. This alteration is visible as fading, discoloration, chalking, flaking, and spalling of several regions of light to medium yellow paint. Since that time, synchrotron radiation-based techniques including elemental and spectroscopic imaging, as well as X-ray scattering have been employed to locate and identify the alteration products observed in this and related works by Henri Matisse. This information is necessary to formulate one or multiple mechanisms for degradation of Matisse's paints from this period, and thus ensure proper environmental conditions for the storage and the display of his works. This paper focuses on 2D full-field X-ray Near Edge Structure imaging, 2D micro-X-ray Diffraction, X-ray Fluorescence, and Fourier Transform Infra-red imaging of the altered paint layers to address one of the long-standing questions about cadmium yellow alteration—the roles of cadmium carbonates and cadmium sulphates found in the altered paint layers. These compounds have often been assumed to be photo-oxidation products, but could also be residual starting reagents from an indirect wet process synthesis of CdS. The data presented here allow identifying and mapping the location of cadmium carbonates, cadmium chlorides, cadmium oxalates, cadmium sulphates, and cadmium sulphides in thin sections of altered cadmium yellow paints from The Joy of Life and Matisse's Flower Piece (1906, The Barnes Foundation). Distribution of various cadmium compounds confirms that cadmium carbonates and sulphates are photo-degradation products in The Joy of Life, whereas in Flower Piece, cadmium carbonates appear to have been a [(partially) unreacted] starting reagent for the yellow paint, a role

  6. Arsenic-cadmium interaction in rats.

    Science.gov (United States)

    Díaz-Barriga, F; Llamas, E; Mejía, J J; Carrizales, L; Santoyo, M E; Vega-Vega, L; Yáñez, L

    1990-11-01

    Simultaneous exposure to cadmium and arsenic is highly probable in the urban area of San Luis Potosi, Mexico due to common localization of copper and zinc smelters. Therefore, in this work, rats were intraperitoneally exposed either to cadmium or arsenic alone, or simultaneously to both metals. The effects of these treatments on three different toxicological parameters were studied. Cadmium modified the LD50 of arsenic and conversely arsenic modified the LD50 for cadmium. At the histopathological level, arsenic appeared to protect against the cadmium effects, especially on testes. This protective effect seemed to be related to the glutathione levels found in this tissue: rats exposed to both arsenic and cadmium, presented glutathione values intermediate to those observed after exposure to either metal alone; arsenic had the highest value and cadmium the lowest. In liver, rats exposed to arsenic, cadmium or arsenic and cadmium, presented glutathione values below those in the saline group, with the lowest value corresponding to the arsenic and cadmium treatment. The results appear to support the proposed interaction between arsenic and cadmium and coexposure to both metals seems to alter certain effects produced by either metal alone. PMID:2219140

  7. Determination of cadmium in biological samples.

    Science.gov (United States)

    Klotz, Katrin; Weistenhöfer, Wobbeke; Drexler, Hans

    2013-01-01

    Analyses of cadmium concentrations in biological material are performed using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS), but also electrochemical methods, neutron activation analysis (NAA), and X-ray fluorescence spectrometry (XRF). The predominant sample matrices include blood, plasma, serum, and urine, as well as hair, saliva, and tissue of kidney cortex, lung, and liver. While cadmium in blood reveals rather the recent exposure situation, cadmium in urine reflects the body burden and is an indicator for the cumulative long term exposure.After chronic exposure, cadmium accumulates in the human body and causes kidney diseases, especially lesions of proximal tubular cells. A tubular proteinuria causes an increase in urinary excretion of microproteins. Excretions of retinol binding protein (RBP), β2-microglobulin (β2-M), and α1-microglobulin are validated biomarkers for analyzing cadmium effects. For this purpose, immunological procedures such as ELISA, and radio- and latex-immunoassays are used.However, proteinuria is not specific to cadmium, but can also occur after exposure to other nephrotoxic agents or due to various kidney diseases. In summary, cadmium in urine and blood are the most specific biomarkers of cadmium exposure. A combination of parameters of exposure (cadmium in blood, cadmium in urine) and parameters of effect (e.g., β2-M, RBP) is required to reveal cadmium-induced nephrological effects. PMID:23430771

  8. Insulin Expression in Rats Exposed to Cadmium

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objectives To investigate the effects of cadmium exposure on insulin expression in rats. Methods Eighteen adult SD assessed. The levels of cadmium and zinc in pancreas, blood and urine glucose, serum insulin and urine NAG (N-acyetyl-β-glucosaminidase) were determined. The gene expressions of metallothionein (MT) and insulin were also measured,and the oral glucose tolerance tests (OGTT) were carried out. Results The contents of cadmium in pancreas in cadmium-treated rats were higher than that in the control group, which was associated with slight increase of zinc in pancreas.not change significantly after cadmium administration, and the UNAG had no change in Cd-treated group. The gene expression the change of the expression of insulin, MT-Ⅰ and MT-Ⅱ genes. Cadmium can influence the biosynthesis of insulin, but does not induce the release of insulin. The dysfunction of pancreas occurs earlier than that of kidney after administration of cadmium.

  9. Gene networks and toxicity pathways induced by acute cadmium exposure in adult largemouth bass (Micropterus salmoides)

    Energy Technology Data Exchange (ETDEWEB)

    Mehinto, Alvine C., E-mail: alvinam@sccwrp.org [Southern California Coastal Water Research Project, Costa Mesa, CA 92626 (United States); Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Prucha, Melinda S. [Department of Human Genetics, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322 (United States); Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Colli-Dula, Reyna C.; Kroll, Kevin J.; Lavelle, Candice M.; Barber, David S. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Vulpe, Christopher D. [Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720 (United States); Denslow, Nancy D. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States)

    2014-07-01

    Highlights: • Low-level acute cadmium exposure elicited tissue-specific gene expression changes. • Molecular initiating events included oxidative stress and disruption of DNA repair. • Metallothionein, a marker of metal exposure, was not significantly affected. • We report effects of cadmium on cholesterol metabolism and steroid synthesis. • Diabetic complications and impaired reproduction are potential adverse outcomes. - Abstract: Cadmium is a heavy metal that can accumulate to toxic levels in the environment leading to detrimental effects in animals and humans including kidney, liver and lung injuries. Using a transcriptomics approach, genes and cellular pathways affected by a low dose of cadmium were investigated. Adult largemouth bass were intraperitoneally injected with 20 μg/kg of cadmium chloride (mean exposure level – 2.6 μg of cadmium per fish) and microarray analyses were conducted in the liver and testis 48 h after injection. Transcriptomic profiles identified in response to cadmium exposure were tissue-specific with the most differential expression changes found in the liver tissues, which also contained much higher levels of cadmium than the testis. Acute exposure to a low dose of cadmium induced oxidative stress response and oxidative damage pathways in the liver. The mRNA levels of antioxidants such as catalase increased and numerous transcripts related to DNA damage and DNA repair were significantly altered. Hepatic mRNA levels of metallothionein, a molecular marker of metal exposure, did not increase significantly after 48 h exposure. Carbohydrate metabolic pathways were also disrupted with hepatic transcripts such as UDP-glucose, pyrophosphorylase 2, and sorbitol dehydrogenase highly induced. Both tissues exhibited a disruption of steroid signaling pathways. In the testis, estrogen receptor beta and transcripts linked to cholesterol metabolism were suppressed. On the contrary, genes involved in cholesterol metabolism were highly

  10. Iron monosulfide as a scavenger for dissolved hexavalent chromium and cadmium.

    Science.gov (United States)

    Jo, S; Lee, J Y; Kong, S H; Choi, J; Park, J W

    2008-09-01

    Iron sulfide minerals are common components of soil/sedimentary environments. Reactions near the surfaces of iron sulfides play important roles in metal retention, mobility, and bioavailability. A series of batch experiments was conducted to study the removal of aqueous chromium and cadmium by iron monosulfide. Hexavalent chromium was reduced to Cr(III) by iron monosulfide with simultaneous precipitation of chromium and iron oxyhydroxide. In contrast to chromium, the primary retention mechanism of cadmium by iron monosulfide was lattice exchange. Surface adsorption to iron monosulfide and precipitation with sulfide on the iron monosulfide surface also contributed to the removal of aqueous cadmium. New phases of both chromium and cadmium were confirmed with transmission electron microscopy. The solution pH was an important factor in this research; it can change particle surface charge and metal species, hence affecting the removal of chromium, but not cadmium. Ferrous ions without FeS exhibited less Cr(VI) removal than with FeS, which might be owing to sulfides from FeS and the existence of the solid phase. Iron monosulfide exhibited higher removal efficiency for chromium and cadmium than zero valent iron and other iron oxide minerals, and the synergistic effect of ferrous iron and sulfide appeared to cause this result.

  11. Cadmium bound to metal rich granules and exoskeleton from Gammarus pulex causes increased gut lipid peroxidation in zebrafish following single dietary exposure

    Energy Technology Data Exchange (ETDEWEB)

    Khan, F.R., E-mail: fkhan@wlu.ca [Nutritional Sciences Division, King' s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH (United Kingdom); Bury, N.R.; Hogstrand, C. [Nutritional Sciences Division, King' s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH (United Kingdom)

    2010-01-31

    There has been a growing interest in establishing how the sub-cellular distribution of metals in macro-invertebrate prey affects metal trophic bioavailability and toxicity. In this study, the crustacean Gammarus pulex was exposed to 300 {mu}g Cd l{sup -1} spiked with {sup 109}Cd for 13 days, from which the two principal metal containing sub-cellular fractions, the metallothionein-like protein (MTLP) and the metal rich granule and exoskeleton (MRG + exo) were isolated. These fractions were produced at equal metal content, incorporated into gelatin and fed to zebrafish as a single meal; assimilation efficiency (AE), carcass and gut tissue metal concentrations and gut lipid peroxidative damage measured as malondialdehyde (MDA) were assessed. The AE of cadmium bound to the MTLP fraction was 32.1 {+-} 5.6% which was significantly greater than the AE of MRG + exo bound Cd, 13.0 {+-} 2.1% (p < 0.05). Of the metal retained by the fish at 72 h post-feeding, 94% of MTLP-Cd had been incorporated into the carcass, whereas a significant proportion (46%) of MRG + exo-Cd, although assimilated, appeared to remain associated with intestinal tissue. However, this did not translate into a gut tissue concentration difference with 6.8 {+-} 1.2 ng Cd g{sup -1} in fish fed MTLP-Cd compared to 9.5 {+-} 1.4 ng Cd g{sup -1} in fish fed MRG + exo fraction. Both feeds led to significantly increased MDA levels compared to the control group (gelatin only feed), but MRG + exo feed caused significantly more oxidative damage than the MTLP feed (p < 0.01). Thus, MTLP-Cd is more bioavailable than the cadmium bound to granules and exoskeleton, but it was the latter fraction, largely considered as having limited bioavailability, that appeared to exert a greater localised oxidative injury to the digestive tract of zebrafish.

  12. Fractionation and solubility of cadmium in paddy soils amended with porous hydrated calcium silicate

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiu-lan; Saigusa Masaihiko

    2007-01-01

    Previous studies have shown that porous hydrated calcium silicate(PS)is very effective in decreasing cadmium(Cd)content in brown rice.However,it is unclear whether me PS influences cadmium transformation in soil.The present study examined the effect of PS on pH,cadmium transformation and cadmium solubility in Andosol and Alluvial soil,and also compared its effects with CaCO3,acidic porous hydrated calcium silicate(APS)and silica gel.Soil cadmium was operationally fractionationed into exchangeable(Exch),bound to carbonates(Carb).bound to iron and manganese oxides(FeMnOx),bound to organic matters(OM)and residual(Res)fraction.ApplicatiOn of PS and CaCO3 at hig rates enhanced soil pH,while APS and silica gel did not obviously change soil pH.PS and CaCO3 also increased the FeMnOx-Cd in Andosol and Carb-Cd in Alluvial soil,thus reducing the Exch-Cd in me tested soils.However,PS was less effecfive than CaCO3 at the same application rate.Cadmium fractions in the two soils were not changed by the treatments of APS and silica gel.There were no obvious differences in the solubility of cadmium in soils treated with PS,APS,silica gel and CaCO3 except Andosol treated 2.0%CaCO3 at the same pH of soil-CaCl2 suspensions.These findings suggested that the decrease of cadmium availability in soil was mainly attributed to the increase of soil pH caused by PS.

  13. SNF1-related protein kinases type 2 are involved in plant responses to cadmium stress.

    Science.gov (United States)

    Kulik, Anna; Anielska-Mazur, Anna; Bucholc, Maria; Koen, Emmanuel; Szymanska, Katarzyna; Zmienko, Agnieszka; Krzywinska, Ewa; Wawer, Izabela; McLoughlin, Fionn; Ruszkowski, Dariusz; Figlerowicz, Marek; Testerink, Christa; Sklodowska, Aleksandra; Wendehenne, David; Dobrowolska, Grazyna

    2012-10-01

    Cadmium ions are notorious environmental pollutants. To adapt to cadmium-induced deleterious effects plants have developed sophisticated defense mechanisms. However, the signaling pathways underlying the plant response to cadmium are still elusive. Our data demonstrate that SnRK2s (for SNF1-related protein kinase2) are transiently activated during cadmium exposure and are involved in the regulation of plant response to this stress. Analysis of tobacco (Nicotiana tabacum) Osmotic Stress-Activated Protein Kinase activity in tobacco Bright Yellow 2 cells indicates that reactive oxygen species (ROS) and nitric oxide, produced mainly via an l-arginine-dependent process, contribute to the kinase activation in response to cadmium. SnRK2.4 is the closest homolog of tobacco Osmotic Stress-Activated Protein Kinase in Arabidopsis (Arabidopsis thaliana). Comparative analysis of seedling growth of snrk2.4 knockout mutants versus wild-type Arabidopsis suggests that SnRK2.4 is involved in the inhibition of root growth triggered by cadmium; the mutants were more tolerant to the stress. Measurements of the level of three major species of phytochelatins (PCs) in roots of plants exposed to Cd(2+) showed a similar (PC2, PC4) or lower (PC3) concentration in snrk2.4 mutants in comparison to wild-type plants. These results indicate that the enhanced tolerance of the mutants does not result from a difference in the PCs level. Additionally, we have analyzed ROS accumulation in roots subjected to Cd(2+) treatment. Our data show significantly lower Cd(2+)-induced ROS accumulation in the mutants' roots. Concluding, the obtained results indicate that SnRK2s play a role in the regulation of plant tolerance to cadmium, most probably by controlling ROS accumulation triggered by cadmium ions.

  14. Regulatory policy governing cadmium-telluride photovoltaics: A case study contrasting life cycle management with the precautionary principle

    International Nuclear Information System (INIS)

    Market projections for cadmium-telluride (CdTe) thin-film photovoltaics (PV) are tempered by global environmental policies based on the precautionary principle which restrict electronic products containing cadmium, a known human carcinogen. An alternative to the precautionary principle is life cycle management, which involves manufacturers assuming product stewardship from beginning to end of product life. Both approaches have the aim of minimizing environmental contamination, but attempt to do so in different ways. Restrictions on electronic products containing cadmium by the precautionary principle-based restriction of hazardous substances (RoHS) directive in the European Union and a similar policy in China are presented, relative to their potential impact on CdTe PV. Life cycle environmental risks with respect to potential release of cadmium to the environment are also presented for routine operation of CdTe PV panels, potential catastrophic release of cadmium from a residential fire, and at the end of the product life. There is negligible risk of environmental cadmium contamination during routine operation and insignificant risk during catastrophic exposure events such as fire. At the end of the product life, risks of contamination are minimized by take-back programs that may be paid for by insurance premiums incorporated into the cost of the product. Therefore, policies based on the precautionary principle that could potentially ban the product based on its cadmium content may not be warranted

  15. Cadmium detoxification processes in the digestive gland of cephalopods in relation to accumulated cadmium concentrations

    OpenAIRE

    Bustamante, Paco; Cosson, Richard; Gallien, Isabelle; Caurant, Florence; Miramand, Pierre

    2002-01-01

    International audience The high concentrations of cadmium recorded in the digestive gland of cephalopods from various temperate and subpolar waters suggest that these molluscs have developed efficient cadmium detoxification mechanisms. The subcellular distribution of cadmium in the digestive gland cells was investigated in seven cephalopod species from the Bay of Biscay (France) and the Faroe Islands. In most species, cadmium was mainly found in the cytosolic fraction of the digestive glan...

  16. Cadmium content of plants as affected by soil cadmium concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lehoczky, E. [Pannon Univ. of Agricultural Sciences, Keszthely (Hungary); Szabados, I.; Marth, P. [Plant Health and Soil Conservation Station, Higany (Hungary)

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  17. Cadmium Exposure and Pancreatic Cancer in South Louisiana

    OpenAIRE

    Luckett, Brian G.; L. Joseph Su; Rood, Jennifer C.; Elizabeth T. H. Fontham

    2012-01-01

    Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana). We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney c...

  18. Crystal Structure and Characterization of a New Eight Coordinated Cadmium Complex

    Energy Technology Data Exchange (ETDEWEB)

    Hakimi, Mohammad; Moeini, Keyvan; Mardani, Zahra; Khorrami, Farzaneh [Payame Noor Univ., Tehran (Iran, Islamic Republic of)

    2013-06-15

    In this work, a new cadmium complex [Cd(L)(CH{sub 3}COO){sub 2}]-2H{sub 2}O (1) with the ligand L, N,N'-bis(2-pyridinecar-boxalidene)-1,2-cyclohexanediamine was prepared and identified by elemental analysis, FT-IR, Raman, {sup 1}H NMR spectroscopy and single-crystal X-ray diffraction. The cadmium atom in the crystal structure of 1 has distorted triangular dodecahedral geometry by coordination of the four nitrogen atoms of L and four oxygen atoms of the two acetate ions. Two water molecules are also incorporated in the crystal network. The O-H···O hydrogen bonds present in the crystal structure of 1. In this work, three structural surveys including coordination numbers of the cadmium atom, coordination modes of L and resonance in pyridine-2-ylmethanimine-based compounds are presented.

  19. Determination of Cadmium in Water by Flame Atomic Absorption Spectrometry after Separation/Preconcentration with Graphene Oxide/Maifanite%氧化石墨烯/麦饭石分离富集-火焰原子吸收法测定水中镉

    Institute of Scientific and Technical Information of China (English)

    卞战强; 樊伟; 田向红; 罗庆; 张娟

    2013-01-01

    通过浸渍法制备了新型纳米氧化石墨烯/麦饭石(GO/MFS)复合吸附材料,并用于镉的分离富集.以火焰原子吸收法为检测手段,研究了GO/MFS复合吸附材料对水中Cd(Ⅱ)的吸附性能.结果表明:当pH为9.0时,GO/MFS复合吸附材料用量为20 mg,振荡10 min,Cd(Ⅱ)可被吸附材料定量富集,最大吸附容量为111.1 mg/g.吸附等温线均能符合Langmuir和Freundlich等温线模型,说明该吸附体系是一个单层覆盖与多层吸附相结合的模式.被吸附的Cd(Ⅱ)可用0.15 mol/L HNO3定量洗脱.方法测定Cd(Ⅱ)的线性范围为0.04~2.0 mg/L,检出限为9.6 μg/L;对40μg/L Cd(Ⅱ)测定的相对标准偏差(RSD)为2.5%(n=9).该方法具有操作简单、分析时间短、线性范围宽等优点.用该法对自来水中Cd(Ⅱ)进行加标测定,回收率101%~103%.%A new nano material graphene oxide/maifanite(GO/MFS) was prepared by using the wet impregnation method for separation-preconcentration of trace cadmium.By means of the determination of flame atomic absorption spectrometry(FAAS),the adsorption behavior of cadmium ions on GO/MFS was investigated.The Langmuir and Freundlich adsorption models fitted well with the experimental equilibrium data.The maximum adsorption capacity was 111.1 mg/g by the Langmuir adsorption models.The adsorbed Cd(Ⅱ) could be quantitatively eluted using 0.15 mol/L HNO3.A linear response of cadmium was obtained in the range of 0.04-2.0 mg/L with a detection limit of 9.6 μg/L.Under optimum conditions,the relative standard deviation(RSD) was 2.5%(n=9 ;c=40 μg/L).This proposed method had a wide measurement scope,short testing time and simple operation and has been applied to the determination of trace cadmium at different concentration levels in water samples,and the recovery was in the range of 101%-103%.It could meet the requirement of water analysis.

  20. Zone refining of cadmium and related characterization

    Indian Academy of Sciences (India)

    N R Munirathnam; D S Prasad; Ch Sudheer; J V Rao; T L Prakash

    2005-06-01

    We present the zone refining results of cadmium using horizontal resistive zone refiner under constant flow of moisture free hydrogen gas. The boron impurity in cadmium can be avoided using quartz (GE 214 grade) boat in lieu of high pure graphite boat. The analytical results using inductively coupled plasma optical emission spectrometry (ICPOES) show that majority of the impurities are less than the detection limits. Comparatively, zinc is the most difficult impurity element to remove in cadmium matrix by zone refining.

  1. Electrodialytic Removal of Cadmium from Straw Ash

    DEFF Research Database (Denmark)

    Hansen, Henrik; Ottosen, Lisbeth M.; Villumsen, Arne;

    1999-01-01

    A problem with flyash from straw and wood combustion is the high level of heavy metals, especially cadmium. Two electrodialytic remediation experiments were carried out on cadmium polluted flyash from straw combustion. The flyash could be cleaned to 1/3 of its initial level after 24 days...... of remediation. Further removal of cadmium could be possible with longer remediation time or a higher current density...

  2. Femtosecond laser ablation of cadmium tungstate for scintillator arrays

    Science.gov (United States)

    Richards, S.; Baker, M. A.; Wilson, M. D.; Lohstroh, A.; Seller, P.

    2016-08-01

    Ultrafast pulsed laser ablation has been investigated as a technique to machine CdWO4 single crystal scintillator and segment it into small blocks with the aim of fabricating a 2D high energy X-ray imaging array. Cadmium tungstate (CdWO4) is a brittle transparent scintillator used for the detection of high energy X-rays and γ-rays. A 6 W Yb:KGW Pharos-SP pulsed laser of wavelength 1028 nm was used with a tuneable pulse duration of 10 ps to 190 fs, repetition rate of up to 600 kHz and pulse energies of up to 1 mJ was employed. The effect of varying the pulse duration, pulse energy, pulse overlap and scan pattern on the laser induced damage to the crystals was investigated. A pulse duration of ≥500 fs was found to induce substantial cracking in the material. The laser induced damage was minimised using the following operating parameters: a pulse duration of 190 fs, fluence of 15.3 J cm-2 and employing a serpentine scan pattern with a normalised pulse overlap of 0.8. The surface of the ablated surfaces was studied using scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy and X-ray photoelectron spectroscopy. Ablation products were found to contain cadmium tungstate together with different cadmium and tungsten oxides. These laser ablation products could be removed using an ammonium hydroxide treatment.

  3. High efficiency thin film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.; Chu, Shirley S.; Britt, J.; Chen, G.; Ferekides, C.; Schultz, N.; Wang, C.; Wu, C. Q.

    1992-12-01

    Cadmium sulfide (CdS), grown from an aqueous solution, and zinc oxide (ZnO), cadmium zinc sulfide (Cd1-xZnxS), and zinc selenide (ZnSe), deposited by metalorganic chemical vapor deposition (MOCVD), have been used as the window for thin film cadmium telluride (CdTe) solar cells. Thin film solar cells were prepared by the successive deposition of the window and p-CdTe (by MOCVD and close-spaced sublimation, CSS) on SnO2:F/glass substrates. CdS/CdTe(CSS) solar cells show considerably better characteristics than CdS/CdTe(MOCVD) solar cells because of the better microstructure of CSS CdTe films. Total area conversion efficiency of 14.6%, verified by the National Renewable Energy Laboratory, has been achieved for solar cells of about 1 cm2 area. Solar cell prepared by using ZnO, ZnSe, or Cd1-xZnxS as window have significantly lower photovoltage than CdS/CdTe solar cells.

  4. Bio-Sensing of Cadmium(II Ions Using Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Jindrich Kynicky

    2011-11-01

    Full Text Available Cadmium, as a hazardous pollutant commonly present in the living environment, represents an important risk to human health due to its undesirable effects (oxidative stress, changes in activities of many enzymes, interactions with biomolecules including DNA and RNA and consequent potential risk, making its detection very important. New and unique technological and biotechnological approaches for solving this problems are intensely sought. In this study, we used the commonly occurring potential pathogenic microorganism Staphylococcus aureus for the determination of markers which could be used for sensing of cadmium(II ions. We were focused on monitoring the effects of different cadmium(II ion concentrations (0, 1.25, 2.5, 5, 10, 15, 25 and 50 µg mL−1 on the growth and energetic metabolism of Staphylococcus aureus. Highly significant changes have been detected in the metabolism of thiol compounds—specifically the protein metallothionein (0.79–26.82 mmol/mg of protein, the enzyme glutathione S-transferase (190–5,827 µmol/min/mg of protein, and sulfhydryl groups (9.6–274.3 µmol cysteine/mg of protein. The ratio of reduced and oxidized glutathione indicated marked oxidative stress. In addition, dramatic changes in urease activity, which is connected with resistance of bacteria, were determined. Further, the effects of cadmium(II ions on the metabolic pathways of arginine, β-glucosidase, phosphatase, N-acetyl β-D-glucosamine, sucrose, trehalose, mannitol, maltose, lactose, fructose and total proteins were demonstrated. A metabolomic profile of Staphylococcus aureus under cadmium(II ion treatment conditions was completed seeking data about the possibility of cadmium(II ion accumulation in cells. The results demonstrate potential in the application of microorganisms as modern biosensor systems based on biological components.

  5. Effect of Physalis peruviana L. on cadmium-induced testicular toxicity in rats.

    Science.gov (United States)

    Othman, Mohamed S; Nada, Ahmed; Zaki, Hassan S; Abdel Moneim, Ahmed E

    2014-06-01

    Cadmium (Cd) stimulates the production of reactive oxygen species and causes tissue damage. We investigated here the protective effect of Physalis peruviana L. (family Solanaceae) against cadmium-induced testes toxicity in rats. Twenty-eight Wistar albino rats were used. They were divided into four groups (n=7). Group 1 was used as control. Group 2 was intraperitoneally injected with 6.5 mg/kg body weight (bwt) of cadmium chloride for 5 days. Group 3 was orally treated with 200 mg/kg bwt of methanolic extract of physalis (MEPh). Group 4 was pretreated with MEPh before cadmium for 5 days. Changes in body and testes weights were determined. Oxidative stress markers, antioxidant enzymes, and testosterone level were measured. Histopathological changes of testes were examined, and the immunohistochemical staining for the proapoptotic (caspase-3) protein was performed. The injection of cadmium caused a significant decrease in body weight, while a significant increase in testes weight and testes weight index was observed. Pretreatment with MEPh was associated with significant reduction in the toxic effects of Cd as shown by reduced testicular levels of malondialdehyde, nitric oxide, and caspase-3 expression and increased glutathione content, and the activities of superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and testosterone were also increased. Testicular histopathology showed that Cd produced an extensive germ cell apoptosis, and the pretreatment of MEPh in Cd-treated rats significantly reduced Cd-induced testicular damage. On the basis of the above results, it can be hypothesized that P. peruviana L. has a protective effect against cadmium-induced testicular oxidative stress and apoptosis in the rat. PMID:24728876

  6. Global Fitness Profiling Identifies Arsenic and Cadmium Tolerance Mechanisms in Fission Yeast

    Science.gov (United States)

    Guo, Lan; Ganguly, Abantika; Sun, Lingling; Suo, Fang; Du, Li-Lin; Russell, Paul

    2016-01-01

    Heavy metals and metalloids such as cadmium [Cd(II)] and arsenic [As(III)] are widespread environmental toxicants responsible for multiple adverse health effects in humans. However, the molecular mechanisms underlying metal-induced cytotoxicity and carcinogenesis, as well as the detoxification and tolerance pathways, are incompletely understood. Here, we use global fitness profiling by barcode sequencing to quantitatively survey the Schizosaccharomyces pombe haploid deletome for genes that confer tolerance of cadmium or arsenic. We identified 106 genes required for cadmium resistance and 110 genes required for arsenic resistance, with a highly significant overlap of 36 genes. A subset of these 36 genes account for almost all proteins required for incorporating sulfur into the cysteine-rich glutathione and phytochelatin peptides that chelate cadmium and arsenic. A requirement for Mms19 is explained by its role in directing iron–sulfur cluster assembly into sulfite reductase as opposed to promoting DNA repair, as DNA damage response genes were not enriched among those required for cadmium or arsenic tolerance. Ubiquinone, siroheme, and pyridoxal 5′-phosphate biosynthesis were also identified as critical for Cd/As tolerance. Arsenic-specific pathways included prefoldin-mediated assembly of unfolded proteins and protein targeting to the peroxisome, whereas cadmium-specific pathways included plasma membrane and vacuolar transporters, as well as Spt–Ada–Gcn5-acetyltransferase (SAGA) transcriptional coactivator that controls expression of key genes required for cadmium tolerance. Notable differences are apparent with corresponding screens in the budding yeast Saccharomyces cerevisiae, underscoring the utility of analyzing toxic metal defense mechanisms in both organisms. PMID:27558664

  7. Global Fitness Profiling Identifies Arsenic and Cadmium Tolerance Mechanisms in Fission Yeast

    Directory of Open Access Journals (Sweden)

    Lan Guo

    2016-10-01

    Full Text Available Heavy metals and metalloids such as cadmium [Cd(II] and arsenic [As(III] are widespread environmental toxicants responsible for multiple adverse health effects in humans. However, the molecular mechanisms underlying metal-induced cytotoxicity and carcinogenesis, as well as the detoxification and tolerance pathways, are incompletely understood. Here, we use global fitness profiling by barcode sequencing to quantitatively survey the Schizosaccharomyces pombe haploid deletome for genes that confer tolerance of cadmium or arsenic. We identified 106 genes required for cadmium resistance and 110 genes required for arsenic resistance, with a highly significant overlap of 36 genes. A subset of these 36 genes account for almost all proteins required for incorporating sulfur into the cysteine-rich glutathione and phytochelatin peptides that chelate cadmium and arsenic. A requirement for Mms19 is explained by its role in directing iron–sulfur cluster assembly into sulfite reductase as opposed to promoting DNA repair, as DNA damage response genes were not enriched among those required for cadmium or arsenic tolerance. Ubiquinone, siroheme, and pyridoxal 5′-phosphate biosynthesis were also identified as critical for Cd/As tolerance. Arsenic-specific pathways included prefoldin-mediated assembly of unfolded proteins and protein targeting to the peroxisome, whereas cadmium-specific pathways included plasma membrane and vacuolar transporters, as well as Spt–Ada–Gcn5-acetyltransferase (SAGA transcriptional coactivator that controls expression of key genes required for cadmium tolerance. Notable differences are apparent with corresponding screens in the budding yeast Saccharomyces cerevisiae, underscoring the utility of analyzing toxic metal defense mechanisms in both organisms.

  8. Differences in urine cadmium associations with kidney outcomes based on serum creatinine and cystatin C

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Virginia M., E-mail: vweaver@jhsph.edu [Division of Occupational and Environmental Health, Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, 615N. Wolfe St., Rm. 7041, Baltimore, MD 21205 (United States); Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD (United States); Kim, Nam-Soo; Lee, Byung-Kook [Institute of Industrial Medicine, SoonChunHyang University, Asan (Korea, Republic of); Parsons, Patrick J. [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, NY (United States); Spector, June [Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Fadrowski, Jeffrey [Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD (United States); Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD (United States); Jaar, Bernard G. [Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD (United States); Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (United States); Steuerwald, Amy J. [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, NY (United States); Todd, Andrew C. [Department of Preventive Medicine, Mount Sinai School of Medicine, New York, NY (United States); and others

    2011-11-15

    Cadmium is a well-known nephrotoxicant; chronic exposure increases risk for chronic kidney disease. Recently, however, associations between urine cadmium and higher creatinine-based estimated glomerular filtration rate (eGFR) have been reported. Analyses utilizing alternate biomarkers of kidney function allow evaluation of potential mechanisms for these observations. We compared associations of urine cadmium with kidney function measures based on serum cystatin C to those with serum creatinine in 712 lead workers. Mean (standard deviation) molybdenum-corrected urine cadmium, Modification of Diet in Renal Disease (MDRD) eGFR and multi-variable cystatin C eGFR were 1.02 (0.65) {mu}g/g creatinine, and 97.4 (19.2) and 112.0 (17.7) mL/min/1.73 m{sup 2}, respectively. The eGFR measures were moderately correlated (r{sub s}=0.5; p<0.001). After adjustment, ln (urine cadmium) was not associated with serum cystatin-C-based measures. However, higher ln (urine cadmium) was associated with higher creatinine-based eGFRs including the MDRD and an equation incorporating serum cystatin C and creatinine (beta-coefficient=4.1 mL/min/1.73 m{sup 2}; 95% confidence interval=1.6, 6.6). Urine creatinine was associated with serum creatinine-based but not cystatin-C-based eGFRs. These results support a biomarker-specific, rather than a kidney function, effect underlying the associations observed between higher urine cadmium and creatinine-based kidney function measures. Given the routine use of serum and urine creatinine in kidney and biomarker research, additional research to elucidate the mechanism(s) for these associations is essential.

  9. Bioavailability of cadmium from linseed and cocoa

    OpenAIRE

    Hansen, Max; Rasmussen, Rie Romme; Sloth, Jens Jørgen

    2014-01-01

    The exposure of the European population to cadmium from food is high compared with the tolerable weekly intake of 2.5 μg/kg bodyweight set by EFSA in 2009. Only few studies on the bioavailability of cadmium from different food sources has been performed but this information in very important for the food authorities in order to give correct advises to the population. The aim of this study was to investigate the bioavailability of cadmium from whole linseed, crushed linseed, cocoa and cadmium ...

  10. The Epigenetic Effects of Prenatal Cadmium Exposure.

    Science.gov (United States)

    Vilahur, Nadia; Vahter, Marie; Broberg, Karin

    2015-06-01

    Prenatal exposure to the highly toxic and common pollutant cadmium has been associated with adverse effects on child health and development. However, the underlying biological mechanisms of cadmium toxicity remain partially unsolved. Epigenetic disruption due to early cadmium exposure has gained attention as a plausible mode of action, since epigenetic signatures respond to environmental stimuli and the fetus undergoes drastic epigenomic rearrangements during embryogenesis. In the current review, we provide a critical examination of the literature addressing prenatal cadmium exposure and epigenetic effects in human, animal, and in vitro studies. We conducted a PubMed search and obtained eight recent studies addressing this topic, focusing almost exclusively on DNA methylation. These studies provide evidence that cadmium alters epigenetic signatures in the DNA of the placenta and of the newborns, and some studies indicated marked sexual differences for cadmium-related DNA methylation changes. Associations between early cadmium exposure and DNA methylation might reflect interference with de novo DNA methyltransferases. More studies, especially those including environmentally relevant doses, are needed to confirm the toxicoepigenomic effects of prenatal cadmium exposure and how that relates to the observed health effects of cadmium in childhood and later life.

  11. Task-specific ionic liquid for solubilizing metal oxides

    OpenAIRE

    Nockemann, Peter; Thijs, Ben; Pittois, Stijn; Thoen, Jan; Glorieux, Christ; Van Hecke, Kristof; Van Meervelt, Luc; Kirchner, Barbara; Binnemans, Koen

    2006-01-01

    Protonated betaine bis(trifluoromethylsulfonyl) imide is an ionic liquid with the ability to dissolve large quantities of metal oxides. This metal-solubilizing power is selective. Soluble are oxides of the trivalent rare earths, uranium(VI) oxide, zinc(II) oxide, cadmium(II) oxide, mercury(II) oxide, nickel( II) oxide, copper(II) oxide, palladium(II) oxide, lead(II) oxide, manganese(II) oxide, and silver(I) oxide. Insoluble or very poorly soluble are iron(III), manganese(IV), and cobalt oxide...

  12. Curcumin Protects against Cadmium-Induced Vascular Dysfunction, Hypertension and Tissue Cadmium Accumulation in Mice

    Directory of Open Access Journals (Sweden)

    Upa Kukongviriyapan

    2014-03-01

    Full Text Available Curcumin from turmeric is commonly used worldwide as a spice and has been demonstrated to possess various biological activities. This study investigated the protective effect of curcumin on a mouse model of cadmium (Cd—induced hypertension, vascular dysfunction and oxidative stress. Male ICR mice were exposed to Cd (100 mg/L in drinking water for eight weeks. Curcumin (50 or 100 mg/kg was intragastrically administered in mice every other day concurrently with Cd. Cd induced hypertension and impaired vascular responses to phenylephrine, acetylcholine and sodium nitroprusside. Curcumin reduced the toxic effects of Cd and protected vascular dysfunction by increasing vascular responsiveness and normalizing the blood pressure levels. The vascular protective effect of curcumin in Cd exposed mice is associated with up-regulation of endothelial nitric oxide synthase (eNOS protein, restoration of glutathione redox ratio and alleviation of oxidative stress as indicated by decreasing superoxide production in the aortic tissues and reducing plasma malondialdehyde, plasma protein carbonyls, and urinary nitrate/nitrite levels. Curcumin also decreased Cd accumulation in the blood and various organs of Cd-intoxicated mice. These findings suggest that curcumin, due to its antioxidant and chelating properties, is a promising protective agent against hypertension and vascular dysfunction induced by Cd.

  13. Synthesis, spectral, electrochemical, crystal structure studies of two novel di-μ-halo-bis[halo(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline)cadmium(II)] dimer complexes and their thermolysis to nanometal oxides

    Science.gov (United States)

    Warad, Ismail; Abdoh, Muneer; Shivalingegowda, Naveen; Lokanath, Neartur Krishnappagowda; Salghi, Rachid; Al-Nuri, Mohammed; Jodeh, Shehdeh; Radi, Smaail; Hammouti, Belkheir

    2015-11-01

    Two new neutral dimer Cadmium(II) complexes, [Cd2(dmdphphen)2X4] and where X = Cl (complex 1), Br (complex 2), and dmdphphen = 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, were synthesized and characterized by an elemental analysis, UV-Vis, IR, TG/DTA, CV and single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic system with the space group P-1 with unit cell parameters a = 10.1124(8) Å, b = 10.8875(8) Å, c = 11.5730(9) Å, α = 108.323(3)°, β = 107.010(3)°, γ = 91.260(3)° V = 1147.51(15) Å3 and Z = 1. The Cd(II) ions are located in a slightly distorted square-pyramidal geometry. The complexes exhibit a quasi-reversible one electron response at -570 mV vs. Cp2Fe/Cp2Fe+, which has been assigned Cd(II)/Cd(III) couples. TG/DTA result shows that these complexes are very stable and decomposed through one step reaction. Calcination of Complex 1, revealed the formation of Cubic nanoparticle CdO.

  14. Improvement of cadmium phytoremediation after soil inoculation with a cadmium-resistant Micrococcus sp.

    Science.gov (United States)

    Sangthong, Chirawee; Setkit, Kunchaya; Prapagdee, Benjaphorn

    2016-01-01

    Cadmium-resistant Micrococcus sp. TISTR2221, a plant growth-promoting bacterium, has stimulatory effects on the root lengths of Zea mays L. seedlings under toxic cadmium conditions compared to uninoculated seedlings. The performance of Micrococcus sp. TISTR2221 on promoting growth and cadmium accumulation in Z. mays L. was investigated in a pot experiment. The results indicated that Micrococcus sp. TISTR2221significantly promoted the root length, shoot length, and dry biomass of Z. mays L. transplanted in both uncontaminated and cadmium-contaminated soils. Micrococcus sp. TISTR2221 significantly increased cadmium accumulation in the roots and shoots of Z. mays L. compared to uninoculated plants. At the beginning of the planting period, cadmium accumulated mainly in the shoots. With a prolonged duration of cultivation, cadmium content increased in the roots. As expected, little cadmium was found in maize grains. Soil cadmium was significantly reduced with time, and the highest percentage of cadmium removal was found in the bacterial-inoculated Z. mays L. after transplantation for 6 weeks. We conclude that Micrococcus sp. TISTR2221 is a potent bioaugmenting agent, facilitating cadmium phytoextraction in Z. mays L.

  15. Effect of cadmium and glutathione on malic enzyme activity in brown shrimps (Crangon crangon from the Gulf of Gdańsk

    Directory of Open Access Journals (Sweden)

    Edward F. Skorkowski

    2011-09-01

    Full Text Available The high level of cadmium in the abdominal muscle of the brown shrimp Crangon crangon is due to the serious pollution of the water in the Gulf of Gdansk. The inhibition of malic enzyme (ME activity by cadmium, and in consequence the reduced formation of NADPH, could interfere with cellular mechanisms for detoxifying the organism and reducing oxidative stress. The reduced glutathione (GSH concentration in the abdominal muscle of C. crangon was calculated to be 5.8 mM. The objective of this study was to evaluate the part played by GSH in the effect of cadmium on the activity of NADP-dependent malic enzyme from abdominal muscles of brown shrimps. This enzyme is activated by certain divalent cations (Mg, Mn. The results demonstrate that cadmium inhibits ME activity from shrimp muscle, and that GSH and albumin can reduce this cadmium-inhibited NADP-dependent malic enzyme activity.

  16. Grape juice concentrate (G8000(®) ) intake mitigates testicular morphological and ultrastructural damage following cadmium intoxication.

    Science.gov (United States)

    Lamas, Celina A; Gollücke, Andrea P B; Dolder, Heidi

    2015-10-01

    Cadmium is a well-known testicular toxicant, and parts of the world population are exposed chronically by inhalation or by food and water intake. Grape products have been highlighted as important sources of bioactive compounds, having anti-inflammatory, anti-oxidant and metal chelating properties. Since maintenance of tissue morphology is essential for testicular sperm development and hence male fertility, we analysed the protective effect of grape juice concentrate (GJC) (G8000(®) ) consumption on testicular morphology in rats exposed to cadmium. Thus, four groups of male Wistar rats (n = 6 per group), 50 days old, ingested either water or G8000(®) (2 g/kg/day) until they had completed one spermatogenic cycle in adult life (136 days old). Cadmium (1.2 mg / kg) was injected intraperitoneally when the animals were 80 days old into one of the water and one of the G8000 groups; intraperitoneal saline was used as a control in the other two groups. Animals anaesthetised and exsanguinated at 136 days and then perfused with Karnovsky's fixative and then the testes were collected for morphological analysis. We describe evident disruption of testicular morphology by cadmium, with alteration in tissue component proportions, reduced Leydig cells volume and initial signs of an inflammatory process. Ultrastructural analysis showed greater damage, suggesting spermatogenesis disruption. G8000(®) ingestion allowed tissue architecture to be re-established, as was corroborated by our stereological and morphometric findings. Animals from the group where G8000(®) had been administered together with cadmium revealed a significant reduction in macrophages and blood vessel volume, suggesting diminished inflammation, when compared to animals that received only cadmium. Moreover, smaller number of ultrastructural alterations was noted, revealing fewer areas of degeneration and disorganized interstitium. In conclusion, our results demonstrate that GJC consumption prevented the

  17. Grape juice concentrate (G8000(®) ) intake mitigates testicular morphological and ultrastructural damage following cadmium intoxication.

    Science.gov (United States)

    Lamas, Celina A; Gollücke, Andrea P B; Dolder, Heidi

    2015-10-01

    Cadmium is a well-known testicular toxicant, and parts of the world population are exposed chronically by inhalation or by food and water intake. Grape products have been highlighted as important sources of bioactive compounds, having anti-inflammatory, anti-oxidant and metal chelating properties. Since maintenance of tissue morphology is essential for testicular sperm development and hence male fertility, we analysed the protective effect of grape juice concentrate (GJC) (G8000(®) ) consumption on testicular morphology in rats exposed to cadmium. Thus, four groups of male Wistar rats (n = 6 per group), 50 days old, ingested either water or G8000(®) (2 g/kg/day) until they had completed one spermatogenic cycle in adult life (136 days old). Cadmium (1.2 mg / kg) was injected intraperitoneally when the animals were 80 days old into one of the water and one of the G8000 groups; intraperitoneal saline was used as a control in the other two groups. Animals anaesthetised and exsanguinated at 136 days and then perfused with Karnovsky's fixative and then the testes were collected for morphological analysis. We describe evident disruption of testicular morphology by cadmium, with alteration in tissue component proportions, reduced Leydig cells volume and initial signs of an inflammatory process. Ultrastructural analysis showed greater damage, suggesting spermatogenesis disruption. G8000(®) ingestion allowed tissue architecture to be re-established, as was corroborated by our stereological and morphometric findings. Animals from the group where G8000(®) had been administered together with cadmium revealed a significant reduction in macrophages and blood vessel volume, suggesting diminished inflammation, when compared to animals that received only cadmium. Moreover, smaller number of ultrastructural alterations was noted, revealing fewer areas of degeneration and disorganized interstitium. In conclusion, our results demonstrate that GJC consumption prevented the

  18. Study on Extracting Low Concentration Cadmium from Zinc Hydrometallurgy System by Liquid Membrane Crystallizing Technique

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The extraction of low concentration cadmium from a system containing high concentration zinc was studied and got CdS product directly. A new liquid membrane system taking DIPSA, TIBPS as carriers, (NH4)2S as precipitating agent was reported. Precipitating Cd2+ in the internal aq. phase that is used to treat sulfuric acid leaching solution of zinc oxide in zinc hydrometallurgy has gotten satisfied results of extracting cadmium from high concentration zinc. After one-stage of batch process under the optimum liquid membrane conditions, 98.6% transferring rate and 98.1% extracting rate of cadmium was obtained with only less than 1.0% transferring rate of zinc, and the feed solution can be purified very well.

  19. The relationship between body iron stores and blood and urine cadmium concentrations in US never-smoking, non-pregnant women aged 20-49 years

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, Carolyn M., E-mail: 2crgallagher@optonline.net [PhD Program in Population Health and Clinical Outcomes Research, Stony Brook University, NY (United States) and Department of Preventive Medicine, Stony Brook University, Z-8036, Level 3, HSC, Stony Brook, NY 11794-8036 (United States); Chen, John J.; Kovach, John S. [Department of Preventive Medicine, Stony Brook University, Z-8036, Level 3, HSC, Stony Brook, NY 11794-8036 (United States)

    2011-07-15

    Background: Cadmium is a ubiquitous environmental pollutant associated with increased risk of leading causes of mortality and morbidity in women, including breast cancer and osteoporosis. Iron deficiency increases absorption of dietary cadmium, rendering women, who tend to have lower iron stores than men, more susceptible to cadmium uptake. We used body iron, a measure that incorporates both serum ferritin and soluble transferrin receptor, as recommended by the World Health Organization, to evaluate the relationships between iron status and urine and blood cadmium. Methods: Serum ferritin, soluble transferrin receptor, urine and blood cadmium values in never-smoking, non-pregnant, non-lactating, non-menopausal women aged 20-49 years (n=599) were obtained from the 2003-2008 National Health and Nutrition Examination Surveys. Body iron was calculated from serum ferritin and soluble transferrin receptor, and iron deficiency defined as body iron <0 mg/kg. Robust linear regression was used to evaluate the relationships between body iron and blood and urine cadmium, adjusted for age, race, poverty, body mass index, and parity. Results: Per incremental (mg/kg) increase in body iron, urine cadmium decreased by 0.003 {mu}g/g creatinine and blood cadmium decreased by 0.014 {mu}g/L. Iron deficiency was associated with 0.044 {mu}g/g creatinine greater urine cadmium (95% CI=0.020, 0.069) and 0.162 {mu}g/L greater blood cadmium (95% CI=0.132, 0.193). Conclusions: Iron deficiency is a risk factor for increased blood and urine cadmium among never-smoking, pre-menopausal, non-pregnant US women, independent of age, race, poverty, body mass index and parity. Expanding programs to detect and correct iron deficiency among non-pregnant women merits consideration as a potential means to reduce the risk of cadmium associated diseases. - Highlights: {yields} Body iron was calculated from serum ferritin and soluble transferrin receptor. {yields} Body iron was inversely associated with blood

  20. The relationship between body iron stores and blood and urine cadmium concentrations in US never-smoking, non-pregnant women aged 20-49 years

    International Nuclear Information System (INIS)

    Background: Cadmium is a ubiquitous environmental pollutant associated with increased risk of leading causes of mortality and morbidity in women, including breast cancer and osteoporosis. Iron deficiency increases absorption of dietary cadmium, rendering women, who tend to have lower iron stores than men, more susceptible to cadmium uptake. We used body iron, a measure that incorporates both serum ferritin and soluble transferrin receptor, as recommended by the World Health Organization, to evaluate the relationships between iron status and urine and blood cadmium. Methods: Serum ferritin, soluble transferrin receptor, urine and blood cadmium values in never-smoking, non-pregnant, non-lactating, non-menopausal women aged 20-49 years (n=599) were obtained from the 2003-2008 National Health and Nutrition Examination Surveys. Body iron was calculated from serum ferritin and soluble transferrin receptor, and iron deficiency defined as body iron <0 mg/kg. Robust linear regression was used to evaluate the relationships between body iron and blood and urine cadmium, adjusted for age, race, poverty, body mass index, and parity. Results: Per incremental (mg/kg) increase in body iron, urine cadmium decreased by 0.003 μg/g creatinine and blood cadmium decreased by 0.014 μg/L. Iron deficiency was associated with 0.044 μg/g creatinine greater urine cadmium (95% CI=0.020, 0.069) and 0.162 μg/L greater blood cadmium (95% CI=0.132, 0.193). Conclusions: Iron deficiency is a risk factor for increased blood and urine cadmium among never-smoking, pre-menopausal, non-pregnant US women, independent of age, race, poverty, body mass index and parity. Expanding programs to detect and correct iron deficiency among non-pregnant women merits consideration as a potential means to reduce the risk of cadmium associated diseases. - Highlights: → Body iron was calculated from serum ferritin and soluble transferrin receptor. → Body iron was inversely associated with blood and urine cadmium

  1. Synthesis and characterization of inorganic ion exchangers based on mixed oxide tin-titanium to be used in recovery of cadmium and nickel and photoluminescent studies; Sintese e caracterizacao de trocadores ionicos inorganicos a base de oxidos mistos estanho-titanio para utilizacao na recuperacao de cadmio e niquel e estudos fotoluminescentes

    Energy Technology Data Exchange (ETDEWEB)

    Paganini, Paula Pinheiro

    2007-07-01

    This work presents the synthesis, characterization and adsorption studies of inorganic ion exchangers based on mixed tin-titanium oxide for recovery of cadmium and nickel metals from aqueous effluents, discarded in the environment mainly through Ni-Cd battery. The exchangers were synthesized by sol-gel modified method using a mixture of tin(IV) chloride and titanium(III) chloride and ammonium hydroxide, as precursors reagents. The materials obtained: SnO{sub 2}/TiO{sub 2} and SnO{sub 2}/TiO{sub 2}:Eu{sup 3+} were characterized by infrared spectroscopy, thermal analysis, scattering electronic microscopy (SEM), X-ray powder diffraction (XRD) (powder method) and electronic spectroscopy (excitation and emission) for the europium doped exchanger. The same materials also were synthesized in polymeric matrix too and can be used in column, because the synthesized materials showed crystals size in nano metric scale. It was determined by the distribution ratios for metals taking as parameters the influence of pH, the concentration of metals (by adsorption isotherms) and the contact time (by adsorption kinetic). The inorganic ion exchanger presented high exchange capacity with adsorption percent above 90 por cent for the studied conditions, quickly kinetic, heterogeneous exchange surfaces, physic adsorption and spontaneous process of exchange. To the doped exchanger spectroscopy properties were studied and also it was calculated the intensity parameters and it was found a satisfactory quantum yield. (author)

  2. Cadmium Modulates Biofilm Formation by Staphylococcus epidermidis

    NARCIS (Netherlands)

    Wu, Xueqing; Santos, Regiane R.; Fink-Gremmels, Johanna

    2015-01-01

    The aim of the study was to evaluate the effect of cadmium exposure on Staphylococcus epidermidis (ATCC 35984) biofilm formation. Bacteria were cultured in the absence or presence of different concentrations (0-50 mu M) of cadmium. Biofilm formation and bacterial viability were assessed. Quantitativ

  3. Cadmium stress in wheat seedlings: growth, cadmium accumulation and photosynthesis

    DEFF Research Database (Denmark)

    Ci, Dunwei; Jiang, Dong; Wollenweber, Bernd;

    2010-01-01

    Seedlings of wheat (Triticum aestivum L.) cultivars Jing 411, Jinmai 30 and Yangmai 10 were exposed to 0, 10, 20, 30, 40 or 50 μM of CdCl2 in a solution culture experiment. The effects of cadmium (Cd) stress on wheat growth, leaf photon energy conversion, gas exchange, and Cd accumulation in wheat...... parameters were generally depressed by Cd stress, especially under the high Cd concentrations. Cd concentration and accumulation in both shoots and roots increased with increasing external Cd concentrations. Relationships between corrected parameters of growth, photosynthesis and fluorescence and corrected...

  4. An omics based assessment of cadmium toxicity in the green alga Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Jamers, An; Blust, Ronny; De Coen, Wim [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Griffin, Julian L. [Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 2QA (United Kingdom); Jones, Oliver A.H., E-mail: oliver.jones@rmit.edu.au [School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne, VIC 3001 (Australia)

    2013-01-15

    The effects of cadmium were assessed in the freshwater alga Chlamydomonas reinhardtii. Algae were exposed to concentrations of 0, 8.1 or 114.8 {mu}M of cadmium and growth rates, gene transcription and metabolite profiles were examined after 48 and 72 h of exposure. In algae exposed to 8.1 {mu}M Cd, several genes were differentially transcribed after 48 h but no adverse growth related effects were detected. A transient effect on both gene transcription patterns and metabolite profiles could be discerned after 48 h of exposure but the majority of these changes disappeared after 72 h. In contrast, all effects were more pronounced at the 114.8 {mu}M cadmium exposure. Here growth was clearly reduced and transcription of a large number of genes involved in oxidative stress defense mechanisms was differentially increased. Metabolites involved in the glutathione synthesis pathway (an important antioxidant defense) were also affected but the effects of cadmium were found to be more pronounced at the transcript level than in the metabolome, suggesting that the former exhibits greater sensitivity toward cadmium exposure.

  5. An omics based assessment of cadmium toxicity in the green alga Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    The effects of cadmium were assessed in the freshwater alga Chlamydomonas reinhardtii. Algae were exposed to concentrations of 0, 8.1 or 114.8 μM of cadmium and growth rates, gene transcription and metabolite profiles were examined after 48 and 72 h of exposure. In algae exposed to 8.1 μM Cd, several genes were differentially transcribed after 48 h but no adverse growth related effects were detected. A transient effect on both gene transcription patterns and metabolite profiles could be discerned after 48 h of exposure but the majority of these changes disappeared after 72 h. In contrast, all effects were more pronounced at the 114.8 μM cadmium exposure. Here growth was clearly reduced and transcription of a large number of genes involved in oxidative stress defense mechanisms was differentially increased. Metabolites involved in the glutathione synthesis pathway (an important antioxidant defense) were also affected but the effects of cadmium were found to be more pronounced at the transcript level than in the metabolome, suggesting that the former exhibits greater sensitivity toward cadmium exposure.

  6. Immunoassay for Cadmium Detection and Quantification

    Institute of Scientific and Technical Information of China (English)

    GONG-LIANG LIU; JU-FANG WANG; ZHI-YONG LI; SHI-ZHONG LIANG; XIAO-NING WANG

    2009-01-01

    Objective To detect cadmium in environmental and food samples by graphite furnace atomic absorption spectroscopy (GFAAS) and inductively coupled plasma atomic emission spectroscopy (ICPAES). Methods An indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was developed based on a cadmium-specific monoclonal antibody.IC-ELISA for cadmium in environmental and food samples was evaluated. Results IC-ELISA showed an IC50 of 45.6 μg/L with a detection limit of 1.95 μg/L for cadmium,and showed a mean recovery ranging 97.67%-107.08%.The coefficient of variations for intra- and iuterassay was 3.41%-6.61% and 4.70%-9.21%,respectively.The correlation coefficient between IC-ELISA and GFAAS was 0.998. Conclusion IC-ELISA can detect and quantify cadmium residue in environmental or food samples.

  7. Cadmium mobility and accumulation in soils of the European Communities

    NARCIS (Netherlands)

    Fraters B; van Beurden AUCJ

    1993-01-01

    In this overview of the effects of cadmium pollution on agricultural soils in the European Community, both the cadmium loads on agricultural land and the soil sensitivity to cadmium accumulation have been estimated. Cadmium loads have been estimated separately for arable land and grassland. The ef

  8. Reproduction and biochemical responses in Enchytraeus albidus (Oligochaeta) to zinc or cadmium exposures

    Energy Technology Data Exchange (ETDEWEB)

    Novais, Sara C., E-mail: sara.novais@ua.pt [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal); Gomes, Susana I.L. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal); Gravato, Carlos [CIIMAR-Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia e Ecologia, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Guilhermino, Lucia [CIIMAR-Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia e Ecologia, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); ICBAS-Instituto de Ciencias Biomedicas Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Porto (Portugal); De Coen, Wim [University of Antwerp, Department of Biology - E.B.T., Groenenborgerlaan 171 - U.7., B-2020 Antwerp (Belgium); Soares, Amadeu M.V.M.; Amorim, Monica J.B. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)

    2011-07-15

    To better understand chemical modes of action, emphasis has been given to stress responses at lower levels of biological organization. Cholinesterases and antioxidant defenses are among the most used biomarkers due to their crucial role in the neurocholinergic transmission and in cell homeostasis preventing DNA damage, enzymatic inactivation and lipid peroxidation. The main goal of this study was to investigate the effects of zinc and cadmium on survival and reproduction of E. albidus and to assess metals oxidative stress potential and neurotoxic effects at concentrations that affected reproduction. Both metals affected the enchytraeids' survival and reproduction and induced significant changes in the antioxidant defenses as well as increased lipid peroxidation, indicating oxidative damage. This study demonstrates that determining effects at different levels of biological organization can give better information on the physiological responses of enchytraeids in metal contamination events and further unravel the mechanistic processes dealing with metal stress. - Highlights: > Zinc and cadmium influence the survival and reproduction of Enchytraeus albidus. > Oxidative stress and membrane damage occur at reproduction effect concentrations. > Glutathione seems to be important in the antioxidant defense against metals. > Time intervals (2, 4, 8 days) allowed following the evolution of oxidative events. - Zinc and cadmium cause oxidative stress and membrane damage in Enchytraeus albidus at reproduction effect concentrations.

  9. Peculiarities of preparation of cadmium isotopes of high enrichment

    International Nuclear Information System (INIS)

    Cascade equipped by gas centrifuges with regard for requirements to structural materials operating with chemically active compounds (dimethylcadmium) was devised for preparation of high-enriched cadmium isotopes. Solutions of such problems as overcoming of isotope memory, compensation of the effect of isotope overlapping, operative analytical accompanying permitted to optimize separation process and to obtain cadmium isotopes of high enrichment degree: cadmium-116 ∼98.9 %, cadmium-114 ∼98.7 %, cadmium-113 ∼93.3 %, cadmium-112 ∼99.1 %, cadmium-110 ∼95.8 %

  10. Bridged graphite oxide materials

    Science.gov (United States)

    Herrera-Alonso, Margarita (Inventor); McAllister, Michael J. (Inventor); Aksay, Ilhan A. (Inventor); Prud'homme, Robert K. (Inventor)

    2010-01-01

    Bridged graphite oxide material comprising graphite sheets bridged by at least one diamine bridging group. The bridged graphite oxide material may be incorporated in polymer composites or used in adsorption media.

  11. Improvement of cadmium uptake and accumulation in Sedum alfredii by endophytic bacteria Sphingomonas SaMR12: effects on plant growth and root exudates.

    Science.gov (United States)

    Chen, Bao; Zhang, Yibin; Rafiq, Muhammad Tariq; Khan, Kiran Yasmin; Pan, Fengshan; Yang, Xiaoe; Feng, Ying

    2014-12-01

    Inoculating endophytic bacteria was proven as a promising way to enhance phytoremediation. By a hydroponic experiment, the role of this study was to clarify the effects of inoculating endophytic bacterium Sphingomonas SaMR12 on phytoremediation, with special emphasis on changes of cadmium uptake, plant growth, root morphology, and organic acids secretion at different cadmium treated levels (0, 5, 50, and 100 μM). The results showed that SaMR12 inoculation improved the accumulation of cadmium as well as plant biomass, length of roots, number of root tips, and root surface area. Root secretion of oxalic, citric, and succinic acids was also increased after inoculated, which may alleviate the cadmium toxicity to plant or inhibit the rising trend of oxidative stress of plant. The major finding of this work suggested that in the root, SaMR12 improves cadmium bioavailability and absorption facility by increasing root-soil contact area and root organic acid secretion; and in the shoot, SaMR12 increases cadmium tolerance by alleviating oxidative stress of plant, so as to enhance the capability of cadmium extraction by plant.

  12. Ecophysiological tolerance of Lemna gibba L. exposed to cadmium.

    Science.gov (United States)

    Uruç Parlak, Kadiriye; Demirezen Yilmaz, Dilek

    2013-05-01

    In this study, an experiment was carried out to study the process of stress adaptation in Lemna gibba L. grown under cadmium stress (0-20mg Cd L(-1)). The level of photosynthetic pigments and soluble proteins decreased only upon exposure to high Cd concentrations (for pigments 5mg Cd L(-1); for soluble proteins 10mg Cd L(-1)). At the same time, the level of malondialdehyde (MDA) increased with increasing Cd concentration. These results suggested an alleviation of stress that was presumably the result of antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione S-transferase (GST) as well as ascorbate peroxidase (APX), which increased linearly with increasing Cd levels. In addition, the proline content in L. gibba increased with increasing cadmium levels. These findings suggest that Lemna is equipped with an efficient antioxidant mechanism against Cd induced oxidative stress which protects the plant's photosynthetic machinery from damage.We also found that moderate Cd treatment (0.05-5mg L(-1) Cd) alleviated oxidative stress in plants, while the addition of higher amounts of Cd (10-20mg L(-1)) could cause an increasing generation of ROS, which was effectively scavenged by the antioxidative system. PMID:23433556

  13. Response of Pleurotus ostreatus to cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Favero, N.; Bressa, G.; Costa, P. (Univ. of Padua (Italy))

    1990-08-01

    The possibility of utilizing agroindustrial wastes in the production of edible, high-quality products (e.g., mushrooms) implies the risk of bringing toxic substances, such as heavy metals, into the human food chain. Thus, growth in the presence of cadmium and cadmium accumulation limits have been studied in the industrially cultivated fungus P. ostreatus. Fruit body production is substantially unaffected in the presence of 25, 139, and 285 mg Cd/kg of dried substrate. Cadmium concentration in fruit bodies is related to cadmium substrate level, the metal being present at higher levels in caps (22-56 mg/kg dry wt) than in stems (13-36 mg/kg dry wt). Concentration factor (CF), very low in the controls (about 2), further decreases in treated specimens. The presence of a cadmium control mechanism in this fungi species is suggested. Fruit body cadmium levels could, however, represent a risk for P. ostreatus consumers, according to FAO/WHO limits related to weekly cadmium intake.

  14. Application of multiwalled carbon nanotubes treated by potassium permanganate for determination of trace cadmium prior to flame atomic absorption spectrometry

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this study we investigated the enrichment ability of oxidized multiwalled carbon nanotubes (MWCNTs) and established a new method for the determination of trace cadmium in environment with flame atomic absorption spectrometry. The MWCNTs were oxidized by potassium permanganate under appropriate conditions before use as preconcentration packing. Parameters influencing the recoveries of target analytes were optimized. Under optimal conditions, the target analyte exhibited a good linearity (R2=0.9992)over the concentration range 0.5-50 ng/ml. The detection limit and precision of the proposed method were 0.15 ng/ml and 2.06%,respectively. The proposed method was applied to the determination of cadmium in real-world environmental samples and the recoveries were in the range of 91.3%-108.0%. All these experimental results indicated that this new procedure could be applied to the determination of trace cadmium in environmental waters.

  15. Tissue-specific accumulation of cadmium in subcellular compartments of eastern oysters Crassostrea virginica Gmelin (Bivalvia: Ostreidae)

    Energy Technology Data Exchange (ETDEWEB)

    Sokolova, I.M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)]. E-mail: insokolo@uncc.edu; Ringwood, A.H. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Johnson, C. [Johnson C. Smith University, 100 Beatties Ford Road, Charlotte, NC 28216 (United States)

    2005-09-10

    Cadmium distribution was studied in different subcellular fractions of gill and hepatopancreas tissues of eastern oysters Crassostrea virginica. Oysters were exposed for up to 21 days to low sublethal Cd concentrations (25 {mu}g L{sup -1}). Gill and hepatopancreas tissues were sampled and divided into organelle fractions and cytosol by differential centrifugation. Organelle content of different fractions was verified by activities of marker enzymes, citrate synthase and acid phosphatase for mitochondria and lysosomes, respectively. In both tissue types, there was a significant accumulation of cadmium in cytosol reaching 230-350 ng mg{sup -1} protein. Among organelles, mitochondria were the main target for Cd bioaccumulation in gills (250-300 ng mg{sup -1} protein), whereas in hepatopancreas tissues, the highest cadmium accumulation occurred in lysosomes (90-94 ng mg{sup -1} protein). Although 75-83% of total cadmium burden was associated with the cytosol reflecting high volume fraction of this compartment, Cd concentrations in organelle fractions reached levels that could cause dysfunction of mitochondria and lysosomes. Organ- and organelle-specific patterns of cadmium bioaccumulation support our previous in vivo studies, which showed adverse effects of cadmium exposures on mitochondrial oxidation in gills and on the lysosomal system of hepatopancreas. This may have important implications for the development of biomarkers of effect for heavy metals and for understanding the mechanisms of toxic effects of metals.

  16. Multiple effects of cadmium on the photosynthetic apparatus of Avicennia germinans L. as probed by OJIP chlorophyll fluorescence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales-Mendoza, D.; Zapata-Perez, O. [Cinvestav Unidad Merida, Yucatan (Mexico). Dept. de Recursos del Mar; Espadas y Gil, F.; Santamaria, J.M. [Unidad de Biotecnologia, CICY, Yucatan (Mexico)

    2007-03-15

    The toxic effects of cadmium on the photosynthetic apparatus of Avicennia germinans were evaluated by means of the chlorophyll fluorescence transient O-J-I-P. The chlorophyll fluorescence transients were recorded in vivo with high time resolution and analyzed according to the OJIP-test that can quantify the performance of photosystem II. Cadmium-treated plants showed a decrease in yield for primary photochemistry, TR{sup 0}/ABS. The performance index of photosystem II (PSII), PI{sub ABS}, decreased due to cadmium treatment. This performance index is the combination of the indexes of three independent parameters: (1) total number of active reaction centers per absorption (RC/ABS), (2) yield of primary photochemistry (TR{sup 0}/ABS), and (3) efficiency with which a trapped exciton can move an electron into the electron transport chain (ET{sup 0}/TR{sup 0}). Additionally, the F{sub 0}/F{sub v} registered the highest sensitivity to the metal, thus indicating that the water-splitting apparatus of the oxidizing side of PSII is the primary site of action of cadmium. In summary, cadmium affects several targets of photosystem II. More specifically the main targets of cadmium, according to the OJIP-test, can be listed as a decrease in the number of active reaction centers and damage to the activity of the water-splitting complex. (orig.)

  17. Cadmium Toxicity to Ringed Seals (Phoca hispida)

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, R.; Riget, F. F.;

    as laboratory mammals. We have studied possible cadmium induced histopathological changes in the kidneys as well as a demineralisation of the skeletal system (DXA-scanning of lumbal vertebraes). No obvious cadmium induced toxic changes were found. Food composition and physiological adaptations may explain......Cadmium concentrations in kidneys from ringed seals (Phoca hispida) from North West Greenland (Qaanaaq) are high. Concentrations range at level known to induce renal toxic effects (mainly tubulopathy) and demineralisation (osteopenia) of the skeletal system (Fanconi's Syndrome) in humans as well...

  18. Prevention of hepato-renal toxicity of radiation and cadmium by Aloe vera

    International Nuclear Information System (INIS)

    Prevention, control and treatment of cancer remain challenge to the medical world. Development of effective and versatile drugs for cancer treatment is an integral part of the ongoing cancer research. The anti stress, hepato-protective, antioxidant and immune modulating properties of Aloe vera make it an ideal drug for developing anti-tumor drugs. Ionizing radiation has always been a part of the human environment. Along with natural radioactive sources present in the earth crust and cosmic radiation, special medical procedures (radiation therapy) also contribute to our continuous exposure to ionizing radiation. Radiation damage, is to a large extent, caused by the overproduction of reactive oxygen species (ROS), including superoxide anion (O2-), hydroxyl radical (OH) and hydrogen peroxide (H2O2), that overwhelm the levels of antioxidants, resulting in oxidative stress and cellular damage. Efficient defense and repair mechanisms exist in living cells to protect against oxidant species. Humans are subjected to exposure of cadmium pollution through contaminated air, water, food, manufactured goods and occupational hazards. Cadmium stimulates free radical production, resulting in oxidative deterioration of lipids, proteins DNA and initiating various pathological conditions in human and animals once observed, Cadmium is rapidly cleared from the blood and concentrates in various tissues mainly in the liver and kidney causing many metabolic and histological changes. So it was of particular interest to investigate whether Aloe vera administration to mice would decrease the toxicity associated with oxidative stress and thereby reducing the damage induced by cadmium and gamma radiation exposure. For this purpose, six to eight weeks old mice were selected and divided into seven groups on the basis of radiation, cadmium, combined treatment and drug treated. All biochemical parameters of the control groups were compared with respective experimental groups. Value of total

  19. Hibiscus sabdariffa extractivities on cadmium-mediated alterations of human U937 cell viability and activation

    Institute of Scientific and Technical Information of China (English)

    Tebekeme Okoko; Diepreye Ere

    2012-01-01

    Objective:To investigate the effect of the anthocyanin-rich extract of Hibiscus sabdariffa (H. sabdariffa) calyx on the viability of cadmium-treated U937 cells and cadmium-mediated activation of U937-derived macrophages. Methods:The macrophage cell line U937 was treated with cadmium (0.1μmol/L) and later incubated with the anthocyanin-rich extract and cell viability was assessed via trypan blue staining. In the other experiment, the U937 cells were transformed to the macrophage form by treatment with phorbol 12, myristate 13, and acetate and incubated with cadmium (10μmol/L). The anthocyanin-rich extract was added to the cells later and subsequently, the supernatant of each cell culture was analysed for the production of tumour necrosis factor-alpha (TNF-α), interleukin 1 (IL-1), interleukin 6 (IL-6), nitric oxide, and catalase activity as indices for the activation of macrophages. Results:It revealed that the anthocynanin-rich extract significantly (P <0.05) increased the viability of the cells which was suppressed by cadmium when compared to quercetin dihydrate. The extract also reduced the cadmium-mediated production of the markers of macrophage-activation when compared to quercetin dihydrate. In both experiments, the activity of the extract was concentration-dependent (P <0.05). Conclusion:The findings show that H. sabdariffa possesses significant immunoprotective effect. These corroborate the immense reported antioxidant and medicinal potential of the calyces of the plant which could be exploited for pharmacological and neutraceutical advantages.

  20. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method.

    Science.gov (United States)

    Su, Jinzhan; Zhang, Tao; Li, Yufeng; Chen, Yubin; Liu, Maochang

    2016-01-01

    Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS) photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM), X-ray fluorescence-spectrometry (XRF), UV-Vis absorption spectra and X-ray diffraction (XRD) to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na₂S and Na₂SO₃) at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification. PMID:27314320

  1. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method

    Directory of Open Access Journals (Sweden)

    Jinzhan Su

    2016-06-01

    Full Text Available Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM, X-ray fluorescence-spectrometry (XRF, UV-Vis absorption spectra and X-ray diffraction (XRD to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na2S and Na2SO3 at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification.

  2. Market for nickel-cadmium batteries

    Science.gov (United States)

    Putois, F.

    Besides the lead/acid battery market, which has seen a tremendous development linked with the car industry, the alkaline rechargeable battery market has also been expanded for more than twenty years, especially in the field of portable applications with nickel-cadmium batteries. Today, nickel-cadmium batteries have to face newcomers on the market, such as nickel-metal hydride, which is another alkaline couple, and rechargeable lithium batteries; these new battery systems have better performances in some areas. This work illustrates the status of the market for nickel-cadmium batteries and their applications. Also, for two major applications—the cordless tool and the electric vehicles—the competitive situation of nickel-cadmium batteries; facing new systems such as nickel-metal hydride and lithium ion cells are discussed.

  3. RISK ASSESSMENT AND MANAGEMENT OF ENVIRONMENTAL CADMIUM

    Science.gov (United States)

    Cadmium consumed in foods grown on soils contaminated by industrial Cd+Zn discharge has caused renal tubular dysfunction in exposed humans in discrete situations. However, lack of understanding about environmental Cd has caused wide concern that generalpopulations may...

  4. Incorporating Feminist Standpoint Theory

    DEFF Research Database (Denmark)

    Ahlström, Kristoffer

    2005-01-01

    As has been noted by Alvin Goldman, there are some very interesting similarities between his Veritistic Social Epistemology (VSE) and Sandra Harding’s Feminist Standpoint Theory (FST). In the present paper, it is argued that these similarities are so significant as to motivate an incorporation...

  5. Differentiating leucine incorporation of

    NARCIS (Netherlands)

    Yokokawa, T.; Sintes, E.; de Corte, D.; Olbrich, K.; Herndl, G.J.

    2012-01-01

    The abundance (based on catalyzed reporter deposition-fluorescence in situ hybrid ization, CARD-FISH) and leucine incorporation rates of Archaea and Bacteria were determined throughout the water column in the eastern Atlantic. Bacteria dominated throughout the water column, although their contributi

  6. Silver-cadmium alloys: Physical and metallurgical properties. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The bibliography contains citations concerning the metallurgical and physical properties of silver-cadmium alloys, oxides, and sulfides. The phase relationships and crystal structure of this alloy system are presented. Applications for electrical contact devices are discussed extensively. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Some Aspects of Sealed Nickel Cadmium Cells

    Directory of Open Access Journals (Sweden)

    P. K. Saha

    1967-11-01

    Full Text Available Sealed Nickel Cadmium Cell system is termed till today as the most reliable power pack for electronic apparatus specially in low temperature use. This paper brings out the development and production of sealed nickel cadmium cells of pocket plate construction. The author who has gained experience in production of Ni-Cd cells in East Germany discusses also the major problems faced by the battery manufactures of to-day.

  8. Cadmium zinc telluride spectral modeling

    International Nuclear Information System (INIS)

    Cadmium zinc telluride (CZT) detectors are the highest resolution room temperature gamma-ray detectors available for isotopic analysis. As with germanium detectors, accurate isotopic analysis using spectra requires peak deconvolution. The CZT peak shapes are asymmetric, with a long low energy tail. The asymmetry is a result of the physics of the electron/hole transport in the semiconductor. An accurate model of the physics of the electron/hole transport through an electric field will allow the parameterization of the peak shapes as a function of energy. In turn this leads to the ability to perform accurate spectral deconvolution and therefore accurate isotopic analysis. The model and the peak-shape parameterization as a function of energy will be presented

  9. Cadmium leaching from thermal treated and gamma irradiated Mexican aluminosilicates

    Energy Technology Data Exchange (ETDEWEB)

    Davila-Rangel, J.I. [Departamento de Quimica, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Mexico 11801, D.F. (Mexico); Unidad Academica Centro Regional de Estudios Nucleares, Universidad Autonoma de Zacatecas Cipres 10, Frac. La Penuela, Zacatecas, Zacatecas 98068 (Mexico); Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100 Col. Centro C.P. 50000, Toluca, Edo. de Mexico (Mexico); Solache-Rios, M. [Departamento de Quimica, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Mexico 11801, D.F. (Mexico)], E-mail: msr@nuclear.inin.mx

    2008-10-15

    Thermal and radiation effects on the leaching of cadmium from two cadmium exchanged zeolitic tuffs and one clay were determined. The cadmium exchanged aluminosilicates were heated at different temperatures (500, 700, 900 and 1100 {sup o}C), and the materials were then treated with NaCl (1 M and 5 M) and HNO{sub 3} (0.001 M and 1 M) solutions to determine the leaching behaviour of cadmium from the materials. The stability of cadmium in the materials increased as the heating temperature was increased. Cadmium leaching from gamma irradiated and heated materials at 1100 {sup o}C was higher than leaching from non-irradiated samples.

  10. Cadmium leaching from thermal treated and gamma irradiated Mexican aluminosilicates

    International Nuclear Information System (INIS)

    Thermal and radiation effects on the leaching of cadmium from two cadmium exchanged zeolitic tuffs and one clay were determined. The cadmium exchanged aluminosilicates were heated at different temperatures (500, 700, 900 and 1100 oC), and the materials were then treated with NaCl (1 M and 5 M) and HNO3 (0.001 M and 1 M) solutions to determine the leaching behaviour of cadmium from the materials. The stability of cadmium in the materials increased as the heating temperature was increased. Cadmium leaching from gamma irradiated and heated materials at 1100 oC was higher than leaching from non-irradiated samples

  11. Application of photocatalytic cadmium sulfide nanoparticles to detection of enzymatic activities of glucose oxidase and glutathione reductase using oxidation of 3,3′,5,5′-tetramethylbenzidine

    International Nuclear Information System (INIS)

    Highlights: • The light-powered nanosensor fabricated by enzymatic reactions was reported. • The sensor use energy of photons for oxidation of chromogenic enzymatic substrates. • Enzymatic assays for glucose oxidase and glutathione reductase were developed. - Abstract: It was found out that semiconductor CdS nanoparticles (NPs) are able to catalyze photooxidation of the well known chromogenic enzymatic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) by oxygen. The photocatalytical oxidation of TMB does not require hydrogen peroxide and its rate is directly proportional to the quantity of CdS NPs produced in situ through the interaction of Cd2+ and S2− ions in an aqueous medium. This phenomenon was applied to development of colorimetric sensitive assays for glucose oxidase and glutathione reductase based on enzymatic generation of CdS NPs acting as light-powered catalysts. Sensitivity of the developed chromogenic assays was of the same order of magnitude or even better than that of relevant fluorogenic assays. The present approach opens the possibility for the design of simple and sensitive colorimetric assays for a number of enzymes using inexpensive and available TMB as a universal chromogenic compound

  12. Application of photocatalytic cadmium sulfide nanoparticles to detection of enzymatic activities of glucose oxidase and glutathione reductase using oxidation of 3,3′,5,5′-tetramethylbenzidine

    Energy Technology Data Exchange (ETDEWEB)

    Grinyte, Ruta; Garai-Ibabe, Gaizka; Saa, Laura; Pavlov, Valeri, E-mail: vpavlov@cicbiomagune.es

    2015-06-30

    Highlights: • The light-powered nanosensor fabricated by enzymatic reactions was reported. • The sensor use energy of photons for oxidation of chromogenic enzymatic substrates. • Enzymatic assays for glucose oxidase and glutathione reductase were developed. - Abstract: It was found out that semiconductor CdS nanoparticles (NPs) are able to catalyze photooxidation of the well known chromogenic enzymatic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) by oxygen. The photocatalytical oxidation of TMB does not require hydrogen peroxide and its rate is directly proportional to the quantity of CdS NPs produced in situ through the interaction of Cd{sup 2+} and S{sup 2−} ions in an aqueous medium. This phenomenon was applied to development of colorimetric sensitive assays for glucose oxidase and glutathione reductase based on enzymatic generation of CdS NPs acting as light-powered catalysts. Sensitivity of the developed chromogenic assays was of the same order of magnitude or even better than that of relevant fluorogenic assays. The present approach opens the possibility for the design of simple and sensitive colorimetric assays for a number of enzymes using inexpensive and available TMB as a universal chromogenic compound.

  13. Thermal incorporation behavior during the reduction and stabilization of chromium wastes

    OpenAIRE

    Yang, Jun; 楊駿

    2015-01-01

    The possibility of employing periclase to stabilize chromium in chromium wastes into spinel-based ceramics through thermal method was investigated by heating mixture of simulated chromium waste and magnesium oxide. Different types of magnesium oxide precursors were introduced to incorporate chromium oxide into magnesiochromite (MgCr2O4) ranging from 550 ºC to 1350 ºC. Magnesium oxide precursors of both types can effectively incorporate chromium oxide but via different mechanisms. Three main f...

  14. Cadmium potentiates toxicity of cypermethrin in zebrafish.

    Science.gov (United States)

    Yang, Ye; Ye, Xiaoqing; He, Buyuan; Liu, Jing

    2016-02-01

    Co-occurrence of pesticides such as synthetic pyrethroids and metals in aquatic ecosystems raises concerns over their combined ecological effects. Cypermethrin, 1 of the top 5 synthetic pyrethroids in use, has been extensively detected in surface water. Cadmium (Cd) has been recognized as 1 of the most toxic metals and is a common contaminant in the aquatic system. However, little information is available regarding their joint toxicity. In the present study, combined toxicity of cypermethrin and Cd and the underlying mechanisms were investigated. Zebrafish embryos and adults were exposed to the individual contaminant or binary mixtures. Co-exposure to cypermethrin and Cd produced synergistic effects on the occurrence of crooked body, pericardial edema, and noninflation of swim bladder. The addition of Cd significantly potentiated cypermethrin-induced spasms and caused more oxidative stress in zebrafish larvae. Cypermethrin-mediated induction of transcription levels and catalytic activities of cytochrome P450 (CYP) enzyme were significantly down-regulated by Cd in both zebrafish larvae and adults. Chemical analytical data showed that in vitro elimination of cypermethrin by CYP1A1 was inhibited by Cd. The addition of Cd caused an elevation of in vivo cypermethrin residue levels in the mixture-exposed adult zebrafish. These results suggest that the enhanced toxicity of cypermethrin in the presence of Cd results from the inhibitory effects of Cd on CYP-mediated biotransformation of this pesticide. The authors' findings provide a deeper understanding of the mechanistic basis accounting for the joint toxicity of cypermethrin and Cd. PMID:26267556

  15. Bio-Sensing of Cadmium(II) Ions Using Staphylococcus aureus †

    OpenAIRE

    Jindrich Kynicky; Radimir Vrba; Rene Kizek*; Jaromir Hubalek; Vojtech Adam; Libuse Trnkova; Ludmila Krejcova; David Hynek; Eva Jilkova; Jiri Sochor; Ondrej Zitka

    2011-01-01

    Cadmium, as a hazardous pollutant commonly present in the living environment, represents an important risk to human health due to its undesirable effects (oxidative stress, changes in activities of many enzymes, interactions with biomolecules including DNA and RNA) and consequent potential risk, making its detection very important. New and unique technological and biotechnological approaches for solving this problems are intensely sought. In this study, we used the commonly occurring potentia...

  16. Effect of Liming on Cadmium Forms and Its Toxicity in Red Soils

    Institute of Scientific and Technical Information of China (English)

    A.M.FARAH; XIEZHENGMIAO; 等

    1996-01-01

    The effect of liming 4 soils developed from Quaternary red clay and red sandstone on the cadmium forms and its toxicity were investigated.Liming the acid red soils could greatly reduce Cd toxicity to plants because the soluble Cd and organic Cd in the soils decreased significantly while Cd bound to minerals/oxides and residual Cd increased markedly with increasing lime rates(pH).

  17. Reviews of the environmental effects of pollutants: IV. Cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Hammons, A.S.; Huff, J.E.; Braunstein, H.M.; Drury, J.S.; Shriner, C.R.; Lewis, E.B.; Whitfield, B.L.; Towill, L.E.

    1978-06-01

    This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 ..mu..g per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels.

  18. Reviews of the environmental effects of pollutants: IV. Cadmium

    International Nuclear Information System (INIS)

    This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 μg per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels

  19. Cadmium removal by Lemna minor and Spirodela polyrhiza.

    Science.gov (United States)

    Chaudhuri, Devaleena; Majumder, Arunabha; Misra, Amal K; Bandyopadhyay, Kaushik

    2014-01-01

    The present study investigates the ability of two genus of duckweed (Lemna minor and Spirodela polyrhiza) to phytoremediate cadmium from aqueous solution. Duckweed was exposed to six different cadmium concentrations, such as, 0.5,1.0,1.5, 2.0, 2.5, and 3.0 mg/L and the experiment was continued for 22 days. Water samples were collected periodically for estimation of residual cadmium content in aqueous solution. At the end of treatment period plant samples were collected and accumulated cadmium content was measured. Cadmium toxicity was observed through relative growth factor and changes in chlorophyll content Experimental results showed that Lemna minor and Spirodela polyrhiza were capable of removing 42-78% and 52-75% cadmium from media depending upon initial cadmium concentrations. Cadmium was removed following pseudo second order kinetic model Maximum cadmium accumulation in Lemna minor was 4734.56 mg/kg at 2 mg/L initial cadmium concentration and 7711.00 mg/kg in Spirodela polyrhiza at 3 mg/L initial cadmium concentration at the end of treatment period. Conversely in both cases maximum bioconcentration factor obtained at lowest initial cadmium concentrations, i.e., 0.5 mg/L, were 3295.61 and 4752.00 for Lemna minor and Spirodela polyrhiza respectively. The present study revealed that both Lemna minor and Spirodela polyrhiza was potential cadmium accumulator. PMID:24933906

  20. Surface Complexation Modeling in Variable Charge Soils: Prediction of Cadmium Adsorption

    Directory of Open Access Journals (Sweden)

    Giuliano Marchi

    2015-10-01

    Full Text Available ABSTRACT Intrinsic equilibrium constants for 22 representative Brazilian Oxisols were estimated from a cadmium adsorption experiment. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. Intrinsic equilibrium constants were optimized by FITEQL and by hand calculation using Visual MINTEQ in sweep mode, and Excel spreadsheets. Data from both models were incorporated into Visual MINTEQ. Constants estimated by FITEQL and incorporated in Visual MINTEQ software failed to predict observed data accurately. However, FITEQL raw output data rendered good results when predicted values were directly compared with observed values, instead of incorporating the estimated constants into Visual MINTEQ. Intrinsic equilibrium constants optimized by hand calculation and incorporated in Visual MINTEQ reliably predicted Cd adsorption reactions on soil surfaces under changing environmental conditions.

  1. Piriformospora indica confers cadmium tolerance in Nicotiana tabacum.

    Science.gov (United States)

    Hui, Feiqiong; Liu, Jian; Gao, Qikang; Lou, Binggan

    2015-11-01

    Piriformospora indica, a root-colonizing endophytic fungus of Sebacinales, promotes plant growth and confers resistance against biotic and abiotic stresses. In order to confirm the influence of P. indica on growth, proline, malondialdehyde (MDA), chlorophyll, and cadmium (Cd) amounts in Nicotiana tabacum under Cd stress, hydroponics, pot and field trials were conducted. The results showed that P. indica can store Cd in plant roots and reduce leaf Cd content, reduce the concentration of MDA, and increase the proline and chlorophyll content and the activities of catalase, peroxidase, and superoxide dismutase under hydroponic Cd stress. RT-PCR analysis showed that the relative expression level of genes Gsh2, TaPCS1, oas1, GPX, and Hsp70 in colonized plants was 4.3, 1.4, 2.9, 1.7, and 6.9 fold higher than in un-colonized plants respectively. Cd exposure significantly reduced un-colonized plants' agronomic traits compared to P. indica-colonized ones. Our results suggested that P. indica can sequester Cd in roots, so that much less cadmium was transported to leaves, and the increased concentrations of antioxidant enzymes, pigments and proline contents, as well as the higher expression of stress-related phytochelatin biosynthesis genes in P. indica-inoculated plants, may also serve to protect N. tabacum plants against oxidative damage, enhancing Cd tolerance. PMID:26574103

  2. Effects of alternating and direct current in electrocoagulation process on the removal of cadmium from water

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Subramanyan, E-mail: vasudevan65@gmail.com [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India); Lakshmi, Jothinathan; Sozhan, Ganapathy [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India)

    2011-08-15

    Highlights: {yields} Very high removal efficiency of cadmium was achieved by electrocoagulation. {yields} Alternating current (AC) avoids oxide layer and corrosion on anode surface. {yields} Good current transfer between anode and cathode results more removal efficiency. {yields} Compact treatment facility and complete automation. {yields} Aluminum alloy anode prevents residual aluminum in treated water. - Abstract: In practice, direct current (DC) is used in an electrocoagulation processes. In this case, an impermeable oxide layer may form on the cathode as well as corrosion formation on the anode due to oxidation. This prevents the effective current transfer between the anode and cathode, so the efficiency of electrocoagulation processes declines. These disadvantages of DC have been diminished by adopting alternating current (AC) in electrocoagulation processes. The main objective of this study is to investigate the effects of AC and DC on the removal of cadmium from water using aluminum alloy as anode and cathode. The results showed that the removal efficiency of 97.5 and 96.2% with the energy consumption of 0.454 and 1.002 kWh kl{sup -1} was achieved at a current density of 0.2 A/dm{sup 2} and pH of 7.0 using aluminum alloy as electrodes using AC and DC, respectively. For both AC and DC, the adsorption of cadmium was preferably fitting Langmuir adsorption isotherm, the adsorption process follows second order kinetics and the temperature studies showed that adsorption was exothermic and spontaneous in nature.

  3. Improved phytoaccumulation of cadmium by genetically modified tobacco plants (Nicotiana tabacum L.). Physiological and biochemical response of the transformants to cadmium toxicity

    International Nuclear Information System (INIS)

    The response of tobacco plants (Nicotiana tabacum L.)-non-transformed and transformed with a metallothionein gene MThis from Silene vulgaris L. - to increase cadmium supply in the nutrient solution was compared. The transgenic plants accumulated significantly more Cd both in the roots and the leaves. Visual toxicity symptoms and disturbance in water balance were correlated with Cd tissue content. Treatment with 300 μM CdCl2 resulted in inhibition of photosynthesis and mobilization of the ascorbate-glutathione cycle. Treatment with 500 μM CdCl2 led to irreversible damage of photosynthesis and oxidative stress. An appearance of a new peroxidase isoform and changes in the leaf polypeptide pattern were observed at the highest Cd concentration. The level of non-protein thiols gradually increased following the Cd treatment both in transgenic and non-transformed plants. - Genetic transformation of Nicotiana tabacum L. by metallothionein gene improved phytoaccumulation of cadmium

  4. Environmental cadmium and lead exposures and age-related macular degeneration in U.S. adults: The National Health and Nutrition Examination Survey 2005 to 2008

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Erin W. [Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI (United States); Schaumberg, Debra A. [Division of Preventive Medicine, Brigham and Women' s Hospital, Harvard Medical School and Department of Epidemiology, Harvard School of Public Health, Boston, MA (United States); Center for Translational Medicine, Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT (United States); Park, Sung Kyun, E-mail: sungkyun@umich.edu [Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI (United States); Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI (United States)

    2014-08-15

    Age-related macular degeneration (AMD) is a complex disease resulting from the interplay of genetic predisposition and environmental exposures, and has been linked to oxidative stress and inflammatory mechanisms. Lead and cadmium can accumulate in human retinal tissues and may damage the retina through oxidative stress, and may thereby play a role in the development of AMD. We examined associations between blood lead, blood cadmium, and urinary cadmium concentrations and the presence of AMD in 5390 participants aged 40 years and older with blood lead and blood cadmium measures and a subsample of 1548 with urinary cadmium measures in the 2005–2008 National Health and Nutrition Examination Surveys. AMD was identified by grading retinal photographs with a modification of the Wisconsin Age-Related Maculopathy Grading System. The weighted prevalence of AMD was 6.6% (n=426). Controlling for age, gender, race/ethnicity, education and body mass index, adults in the highest blood cadmium quartile had higher odds of AMD compared to the lowest quartile (odds ratio [OR], 1.56; 95% CI, 1.02–2.40), with a significant trend across quartiles (p-trend=0.02). After further adjustment for pack-years of cigarette smoking, estimates were somewhat attenuated (OR, 1.43; 95% CI, 0.91–2.27; p-trend=0.08). Similar associations were found with urinary cadmium. The association between urinary cadmium and AMD was stronger in non-Hispanic whites (NHW) than in non-Hispanic blacks (NHB) (OR, 3.31; 95% CI, 1.37–8.01 for levels above versus below the median among NHW; OR,1.45; 95% CI, 0.40–5.32 for levels above versus below the median among NHB; p-interaction=0.03). We found no association between blood lead levels and AMD. Higher cadmium body burden may increase risk of AMD, particularly among non-Hispanic white individuals; however, additional studies are needed before firm conclusions can be drawn. - Highlights: • We examined the association of cadmium and lead with age

  5. Environmental cadmium and lead exposures and age-related macular degeneration in U.S. adults: The National Health and Nutrition Examination Survey 2005 to 2008

    International Nuclear Information System (INIS)

    Age-related macular degeneration (AMD) is a complex disease resulting from the interplay of genetic predisposition and environmental exposures, and has been linked to oxidative stress and inflammatory mechanisms. Lead and cadmium can accumulate in human retinal tissues and may damage the retina through oxidative stress, and may thereby play a role in the development of AMD. We examined associations between blood lead, blood cadmium, and urinary cadmium concentrations and the presence of AMD in 5390 participants aged 40 years and older with blood lead and blood cadmium measures and a subsample of 1548 with urinary cadmium measures in the 2005–2008 National Health and Nutrition Examination Surveys. AMD was identified by grading retinal photographs with a modification of the Wisconsin Age-Related Maculopathy Grading System. The weighted prevalence of AMD was 6.6% (n=426). Controlling for age, gender, race/ethnicity, education and body mass index, adults in the highest blood cadmium quartile had higher odds of AMD compared to the lowest quartile (odds ratio [OR], 1.56; 95% CI, 1.02–2.40), with a significant trend across quartiles (p-trend=0.02). After further adjustment for pack-years of cigarette smoking, estimates were somewhat attenuated (OR, 1.43; 95% CI, 0.91–2.27; p-trend=0.08). Similar associations were found with urinary cadmium. The association between urinary cadmium and AMD was stronger in non-Hispanic whites (NHW) than in non-Hispanic blacks (NHB) (OR, 3.31; 95% CI, 1.37–8.01 for levels above versus below the median among NHW; OR,1.45; 95% CI, 0.40–5.32 for levels above versus below the median among NHB; p-interaction=0.03). We found no association between blood lead levels and AMD. Higher cadmium body burden may increase risk of AMD, particularly among non-Hispanic white individuals; however, additional studies are needed before firm conclusions can be drawn. - Highlights: • We examined the association of cadmium and lead with age

  6. Relation of asid-volatile sulfide and clay content of sediment to the bioavailability of zinc and cadmium: laboratory plus field experiment

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Organic matter and iron and maganese oxides have been considered as the major affecting factors for metals in anoxic or oxidized sediment. In recent research, clay and sulfide are found as major factors in oxic or oxidized sediments that might affect bioavailability of metals. To test this hypothesis, the influence of sulfide, measured as acid-volatile sulfide (AVS), and clay content on the bioavailability of zinc and cadmium in sediments was examined. Laboratory simulative experiment and field verification experiment were conducted,showing that the bioavailability of zinc and cadmium is strongly correlated to AVS and clay content in sediments. Taking into account both AVS and clay parameters in sediments together can better indicate the bioavailability of zinc and cadmium rather than considering one of them alone.

  7. 2D X-ray and FTIR micro-analysis of the degradation of cadmium yellow pigment in paintings of Henri Matisse

    International Nuclear Information System (INIS)

    The chemical and physical alterations of cadmium yellow (CdS) paints in Henri Matisse's The Joy of Life (1905-1906, The Barnes Foundation) have been recognized since 2006, when a survey by portable X-ray fluorescence identified this pigment in all altered regions of the monumental painting. This alteration is visible as fading, discoloration, chalking, flaking, and spalling of several regions of light to medium yellow paint. Since that time, synchrotron radiation-based techniques including elemental and spectroscopic imaging, as well as X-ray scattering have been employed to locate and identify the alteration products observed in this and related works by Henri Matisse. This information is necessary to formulate one or multiple mechanisms for degradation of Matisse's paints from this period, and thus ensure proper environmental conditions for the storage and the display of his works. This paper focuses on 2D full-field X-ray Near Edge Structure imaging, 2D micro-X-ray Diffraction, X-ray Fluorescence, and Fourier Transform Infra-red imaging of the altered paint layers to address one of the long-standing questions about cadmium yellow alteration - the roles of cadmium carbonates and cadmium sulphates found in the altered paint layers. These compounds have often been assumed to be photo-oxidation products, but could also be residual starting reagents from an indirect wet process synthesis of CdS. The data presented here allow identifying and mapping the location of cadmium carbonates, cadmium chlorides, cadmium oxalates, cadmium sulphates, and cadmium sulphides in thin sections of altered cadmium yellow paints from The Joy of Life and Matisse's Flower Piece (1906, The Barnes Foundation). Distribution of various cadmium compounds confirms that cadmium carbonates and sulphates are photo-degradation products in The Joy of Life, whereas in Flower Piece, cadmium carbonates appear to have been a [(partially) unreacted] starting reagent for the yellow paint, a

  8. 2D X-ray and FTIR micro-analysis of the degradation of cadmium yellow pigment in paintings of Henri Matisse

    Energy Technology Data Exchange (ETDEWEB)

    Pouyet, E. [European Synchrotron Radiation Facility, Grenoble (France); ARC-Nucleart - CEA/Grenoble, Grenoble Cedex 9 (France); Cotte, M. [European Synchrotron Radiation Facility, Grenoble (France); LAMS (Laboratoire d' Archeologie Moleculaire et Structurale) UMR-8220, Ivry-sur-Seine (France); Fayard, B.; Salome, M.; Kieffer, J.; Burghammer, M.; Sette, F. [European Synchrotron Radiation Facility, Grenoble (France); Meirer, F. [Utrecht University, Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht (Netherlands); Mehta, A. [SLAC National Accelerator Laboratory, Stanford Synchrotron radiation Lightsource, Menlo Park, CA (United States); Uffelman, E.S. [Washington and Lee University, Department of Chemistry and Biochemistry, Lexington, VA (United States); Hull, A. [University of Delaware, Department of Chemistry and Biochemistry, Newark, DE (United States); Vanmeert, F.; Janssens, K. [University of Antwerp, AXES Research Group, Department of Chemistry, Antwerp (Belgium); Mass, J. [Winterthur Museum, Scientific Research and Analysis Laboratory, Conservation Department, Winterthur, DE (United States)

    2015-11-15

    The chemical and physical alterations of cadmium yellow (CdS) paints in Henri Matisse's The Joy of Life (1905-1906, The Barnes Foundation) have been recognized since 2006, when a survey by portable X-ray fluorescence identified this pigment in all altered regions of the monumental painting. This alteration is visible as fading, discoloration, chalking, flaking, and spalling of several regions of light to medium yellow paint. Since that time, synchrotron radiation-based techniques including elemental and spectroscopic imaging, as well as X-ray scattering have been employed to locate and identify the alteration products observed in this and related works by Henri Matisse. This information is necessary to formulate one or multiple mechanisms for degradation of Matisse's paints from this period, and thus ensure proper environmental conditions for the storage and the display of his works. This paper focuses on 2D full-field X-ray Near Edge Structure imaging, 2D micro-X-ray Diffraction, X-ray Fluorescence, and Fourier Transform Infra-red imaging of the altered paint layers to address one of the long-standing questions about cadmium yellow alteration - the roles of cadmium carbonates and cadmium sulphates found in the altered paint layers. These compounds have often been assumed to be photo-oxidation products, but could also be residual starting reagents from an indirect wet process synthesis of CdS. The data presented here allow identifying and mapping the location of cadmium carbonates, cadmium chlorides, cadmium oxalates, cadmium sulphates, and cadmium sulphides in thin sections of altered cadmium yellow paints from The Joy of Life and Matisse's Flower Piece (1906, The Barnes Foundation). Distribution of various cadmium compounds confirms that cadmium carbonates and sulphates are photo-degradation products in The Joy of Life, whereas in Flower Piece, cadmium carbonates appear to have been a [(partially) unreacted] starting reagent for the yellow paint, a

  9. Cadmium exposure induces hematuria in Korean adults

    International Nuclear Information System (INIS)

    Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; Ptrend=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk

  10. Cadmium exposure induces hematuria in Korean adults

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Seok [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Kim, Myounghee, E-mail: dkkim73@gmail.com [Department of Dental Hygiene, College of Health Science, Eulji University, Gyeonggi-do 461-713 (Korea, Republic of); Lee, Su Mi [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lee, Jung Pyo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Sejoong [Department of Internal Medicine, Seoul National University Bundang Hospital, Gyeonggi-do 463-707 (Korea, Republic of); Joo, Kwon Wook [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lim, Chun Soo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Yon Su; Kim, Dong Ki [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of)

    2013-07-15

    Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; P{sub trend}=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk.

  11. Hazards to wildlife from soil-borne cadmium reconsidered

    Science.gov (United States)

    Beyer, W.N.

    2000-01-01

    Cadmium is a toxic element that should be included in environmental risk assessments of contaminated soils. This paper argues, however, that hazards to wildlife from cadmium have often been overstated. The literature contains only meager evidence that wild animals have been seriously harmed by cadmium, even at severely contaminated sites. Although some researchers have reported that wildlife have accumulated concentrations of cadmium in their kidneys that were above suggested injury thresholds, the thresholds may be disputed, since they were well below the World Health Organization criterion of 200 mg/kg (wet weight) of cadmium in the renal cortex for protecting human health. Recent risk assessments have concluded that soil cadmium concentrations less than 1 mg/kg are toxic to soil organisms and wildlife, which implies that background concentrations of cadmium naturally found in soils are hazardous. An examination of the databases used to support these assessments suggested that the toxicity of cadmium has been exaggerated.

  12. In situ reduction and functionalization of graphene oxide with l-cysteine for simultaneous electrochemical determination of cadmium(ii), lead(ii), copper(ii), and mercury(ii) ions

    KAUST Repository

    Muralikrishna, S. N.

    2014-01-01

    One pot reduction and functionalization of graphene oxide (GO) with l-cysteine (l-cys-rGO) at the edges and basal planes of the carbon layers are presented. The l-cys-rGO was characterized by X-ray diffraction studies (XRD), X-ray photoelectron spectroscopy (XPS), attenuated infrared spectroscopy (ATIR), and Raman spectroscopy. The surface morphology was studied by scanning electron microscopy (SEM) and transmittance electron microscopy (TEM). The l-cys-rGO was further utilized for the simultaneous electrochemical quantification of environmentally harmful metal ions such as, Cd2+, Pb2+, Cu2+ and Hg2+. Detection limits obtained for these metal ions were 0.366, 0.416, 0.261 and 1.113 μg L-1 respectively. The linear range obtained for Cd2+, Cu2+ and Hg2+ was 0.4 to 2.0 μM and for Pb2+ was 0.4 to 1.2 μM. The detection limits were found to be less than the World Health Organization (WHO) limits. The developed protocol was applied for the determination of the above metal ions in various environmental samples and the results obtained were validated by atomic absorption spectroscopy (AAS). This journal is

  13. In Vitro Assessment of Cadmium Bioavailability in Chinese Cabbage Grown on Different Soils and Its Toxic Effects on Human Health.

    Science.gov (United States)

    Aziz, Rukhsanda; Rafiq, Muhammad Tariq; He, Zhenli; Liu, Di; Sun, Kewang; Xiaoe, Yang

    2015-01-01

    The minimum concentration of cadmium (Cd), by Chinese cabbage grown on Cd contaminated soils that can initiate toxicity in human liver cells using in vitro digestion coupled with Caco-2/HL-7702 cell models was studied. Cadmium bioaccessibility in the gastric phase for yellow soil (YS) cabbage (40.84%) and calcareous soil (CS) cabbage (21.54%) was significantly higher than small intestinal phase with the corresponding values of 21.2% and 11.11%, respectively. Cadmium bioavailability was higher in YS cabbage (5.27%-14.66%) than in CS cabbage (1.12%-9.64%). Cadmium concentrations (>0.74 μg) transported from YS and CS cabbage were able to induce oxidative (MDA, H2O2) stress by inhibiting antioxidant (SOD, GPx) enzyme activities in human liver cells (HL-7702). Additionally the study revealed that the ingestion of Cd contaminated Chinese cabbage grown in acidic soil (yellow soil) weakened the antioxidant defense system under all levels of contamination (2, 6, and 9 mg·kg(-1)) which ultimately escalated the oxidative stress in liver cells; however, in case of CS cabbage, a marked oxidative stress was observed only at 9 mg kg(-1) Cd level of soil. Therefore, it is necessary to monitor Cd concentrations in leafy vegetables grown on acidic soils to minimize human health risk.

  14. Electrothermal atomic absorption spectrometric determination of cadmium and lead in traces in aquatic systems following flotation by two chromium(III) collectors.

    Science.gov (United States)

    Kormusoska, Natasa Bakreska; Cundeva, Katarina; Stafilov, Trajce

    2009-10-01

    A fast flotation method for determination of cadmium and lead in aquatic systems by two chromium(III) collectors is described. The first collector is a colloid precipitate of hydrated chromium(III) oxide, Cr2O3 x xH2O, while the second is a bulk chromium(III) pentamethylenedithiocarbamate, Cr(PMDTC)3. Cadmium and lead present in water are incorporated into the collector mass at pH 7.5 by addition of 20 mg of Cr(III) and 0.4 mmol of pentamethyleneammonium pentamethylenedithiocarbamate, PMA-PMDTC, to 0.5 L water sample. A solid precipitate was separated from the processed water system by air bubbles. After dissolving with strong acid, the solution is tested by electrothermal atomic absorption spectrometry (ETAAS). The limit of detection for Cd by flotation/ETAAS method is 0.002 microg L(-1), while for Pb is 0.04 microg L(-1). The precision of the method is expressed as relative standard deviations ranging of 5.0% for Cd (concentration range from 0.1 to 0.5 microg L(-1)) and 4.25% for Pb (concentration range from 0.5 to 5 microg L(-1)). The characteristic mass (mass that gives an integrated absorbance of 0.0044 s) of 1.06 pg for Cd and 16.7 pg for Pb were obtained. The method was validated by the standard additions and by its application to the reference materials (Surface water-SPS-SW-1, River Thames Water-LGC-6019). PMID:19847715

  15. On the effect of thallium additions on cadmium amalgam potentials

    International Nuclear Information System (INIS)

    A study has been made of the influence of additives of thallium on potentials of cadmium amalgams with thallium contents of 10, 20, 30, and 40 at.% at 20, 40, 60, and 80 deg C. Additives of thallium have been found to shift the potential of cadmium amalgams towards the range of negative values which indicates an increase in the activity of cadmium. A possibility of calculation of the potential shift for heterogeneous cadmium amalgams on introducing thallium has been shown

  16. A comparative investigation of DNA strand breaks, sister chromatid exchanges and K-ras gene mutations induced by cadmium salts in cultured human cells

    International Nuclear Information System (INIS)

    Cadmium (Cd) is a toxic heavy metal of continuing occupational and environmental concern with a wide variety of adverse effects. Several studies have shown that cadmium produces DNA strand breaks, DNA-protein cross-links, oxidative DNA damage, chromosomal aberrations, dysregulation of gene expression resulting in enhanced proliferation, depressed apoptosis and/or altered DNA repair. This study was undertaken to investigate the ability of cadmium chloride (CdCl2) and cadmium sulphate (CdSO4) to induce point mutations in codon 12 of the K-ras protooncogene assessed by polymerase chain reaction-single strand conformation polymorphisms (PCR-SSCP) and RFLP-enriched PCR methods. Also their genotoxic effects were analyzed by the comet assay and sister chromatid exchanges test. The human lung fibroblast cell line MRC-5 was used for the experiments. Sister chromatid exchanges assay (SCEs) frequencies were significantly increased in cells exposed to cadmium salts in relation to controls (p < 0.001). Despite the slow increment observed in the three comet parameters considered when cells were treated with cadmium chloride, significant differences between groups were only found in the variable comet moment (CM) (p < 0.005). On the other hand, when cells were exposed to cadmium sulphate, the Kruskal-Wallis test showed highly significant differences between groups for migration, tail moment and comet moment parameters (p < 0.001). Nevertheless, a null or weak point mutation induction in K-ras protooncogene was detected using polymerase chain reaction-low ionic strength-single strand conformation polymorphisms (PCR-LIS-SSCP) and RFLP-enriched PCR methods when cells were treated with cadmium salts. Thus, inorganic cadmium produces genotoxicity in human lung fibroblast MRC-5 cells, in the absence of significant point mutation of the K-ras gene

  17. Hybrid photocatalysts using graphitic carbon nitride/cadmium sulfide/reduced graphene oxide (g-C3N4/CdS/RGO) for superior photodegradation of organic pollutants under UV and visible light.

    Science.gov (United States)

    Pawar, Rajendra C; Khare, Varsha; Lee, Caroline Sunyong

    2014-09-01

    Graphitic carbon nitride (g-C3N4) was hybridized with CdS nanoparticles and reduced graphene oxide (RGO) sheets using a facile chemical method, for the application of catalytic photodegradation of Rhodamine B and Congo red dyes under irradiation with UV and visible light. Fourier-transform infrared (FTIR) spectroscopy and X-ray photoemission spectroscopy (XPS) analyses confirmed the formation of pure g-C3N4, as well as g-C3N4/CdS, g-C3N4/RGO, and g-C3N4/CdS/RGO composites. The large surface area of the g-C3N4/CdS/RGO composite (70.42 m(2) g(-1)) resulted in rapid dye adsorption onto the surface of the photocatalyst, leading to effective photodegradation of organic pollutants. The addition of CdS and RGO increased the photocatalytic activity of g-C3N4 by a factor of approximately twenty compared with that of the commercially available TiO2 catalyst under visible light, and the g-C3N4/CdS/RGO composite was found to significantly enhance the catalytic effect compared with pure g-C3N4 and with the g-C3N4/CdS and g-C3N4/RGO composites. The superior photocatalytic activity of the g-C3N4/CdS/RGO composite is attributed to enhanced separation of the photogenerated electron-hole pairs, as well as increased visible-light absorption. The improved transport of photoelectrons was consistent with the results of transient photocurrent measurements. Therefore, g-C3N4/CdS/RGO composites using a facile method are applicable to the development of high-efficiency photocatalytic devices for industrial applications. PMID:25001639

  18. Recycling of Spent Nickel-Cadmium Batteries

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A technique for recycling spent nickel-cadmium batteries, which makes separation of cadmium and nickel possible, is developed by laboratory-scale experiments. NH3-H2CO3 aqueous solution was used in this leaching technique. Since neutralization and/or solvent extraction were not required in the separation procedure of nickel and cadmium, the closed systemization of the process becomes possible. Experimental results show that, (1) if the NH3 concentration of leaching solution is sufficiently high and the ratio of H2CO3 to NH3 is properly adjusted, both Ni(OH)2 and Cd(OH)2 react with NH3 and quickly dissolve into leaching solution, and (2) Ni(OH)2 can be converted into insoluble NiO by calcination at 500€癈, and CdO from Cd(OH)2 by calcination maintains good solubility in NH3-H2CO3 aqueous solution. As a conclusion, the recycling technique characterized by two step leaching can be developed based on such changes in dissolution behavior by calcination. Meanwhile, the yields of 99.8% for nickel and 97.6% for cadmium are obtained, and the purities of recovered nickel and cadmium are 99.9% and 98.6%, respectively.

  19. Effect of anions on Toxicity of Cadmium Applied to MIcrobial Biomass in Red Soil

    Institute of Scientific and Technical Information of China (English)

    K.S.KHAN; XIEZHENGMIAO; 等

    1997-01-01

    A laboratory incubation experiment was conducted to elucidat the effects of associated anions on toxicity of cadmium applied to microbial biomass in the red soil. Cadmium was applied at six different levels,i.e.,O(background),5,15,30,60 and 100μg g-1 soil in the form of either cadmium acetate or cadmium chloride. Application of cadmium as cadmium acetate markedly reduced the soil microbial biomass carbon compared to cadmium applied as cadmium chlorde at all the tested levels.Similarly,organic carbon to biomass carbon ration in the soil was markedly increased by increasing the level of the cadmium in the soil as cadmium acetate,while the change wa much smaller in the case of cadmium chloride at the same cadmium levels.The results suggested that due consideration should be given to the source of cadmium while deciding the cadmium levles in experiments.

  20. Cadmium induces cadmium-tolerant gene expression in the filamentous fungus Trichoderma harzianum.

    Science.gov (United States)

    Cacciola, Santa O; Puglisi, Ivana; Faedda, Roberto; Sanzaro, Vincenzo; Pane, Antonella; Lo Piero, Angela R; Evoli, Maria; Petrone, Goffredo

    2015-11-01

    The filamentous fungus Trichoderma harzianum, strain IMI 393899, was able to grow in the presence of the heavy metals cadmium and mercury. The main objective of this research was to study the molecular mechanisms underlying the tolerance of the fungus T. harzianum to cadmium. The suppression subtractive hybridization (SSH) method was used for the characterization of the genes of T. harzianum implicated in cadmium tolerance compared with those expressed in the response to the stress induced by mercury. Finally, the effects of cadmium exposure were also validated by measuring the expression levels of the putative genes coding for a glucose transporter, a plasma membrane ATPase, a Cd(2+)/Zn(2+) transporter protein and a two-component system sensor histidine kinase YcbA, by real-time-PCR. By using the aforementioned SSH strategy, it was possible to identify 108 differentially expressed genes of the strain IMI 393899 of T. harzianum grown in a mineral substrate with the addition of cadmium. The expressed sequence tags identified by SSH technique were encoding different genes that may be involved in different biological processes, including those associated to primary and secondary metabolism, intracellular transport, transcription factors, cell defence, signal transduction, DNA metabolism, cell growth and protein synthesis. Finally, the results show that in the mechanism of tolerance to cadmium a possible signal transduction pathway could activate a Cd(2+)/Zn(2+) transporter protein and/or a plasma membrane ATPase that could be involved in the compartmentalization of cadmium inside the cell. PMID:26349455

  1. Cadmium-113m as a biogeochemical tracer for cadmium in Lake Michigan

    International Nuclear Information System (INIS)

    The Lake Michigan watershed has been sampled for 113mCd. This long-lived metastable isotope of cadmium allowed independent evaluation of cadmium distribution in this dynamic ecosystem. 113mCd analysis was not hampered by contamination or loss. These are problems which have plagued stable cadmium measurements. Sensitivity and specificity were necessary concerns. 113mCd has been preconcentrated from large samples in order to obtain sufficient activity for quantification. Specificity for the gross beta activity measured was secured in a rigorous ion exchange decontamination. Confirmation of the suspected 113mCd beta source was checked by reverse tracer analysis and modified Feather analysis range-energy relationships. The 113mCd activities confirm the expected semiconservative behavior for cadmium. This behavior manifests itself in a long residence time for cadmium in Lake Michigan. The inefficiency of outflow removal, the low sedimentation rate and the unquantified sediment resuspension and release of cadmium are factors contributing to this residence time. Steady state concentration of cadmium in Lake Michigan will increase if present input rates persist

  2. Alleviation of cadmium stress in Solanum lycopersicum L. by arbuscular mycorrhizal fungi via induction of acquired systemic tolerance.

    Science.gov (United States)

    Hashem, Abeer; Abd Allah, E F; Alqarawi, A A; Al Huqail, Asma A; Egamberdieva, D; Wirth, S

    2016-03-01

    Experiments were conducted to evaluate cadmium (Cd) stress-induced changes in growth, antioxidants and lipid composition of Solanum lycopersicum with and without arbuscular mycorrhizal fungi (AMF). Cadmium stress (50 μM) caused significant changes in the growth and physio-biochemical attributes studied. AMF mitigated the deleterious impact of Cd on the parameters studied. Cadmium stress increased malonaldehyde and hydrogen peroxide production but AMF reduced these parameters by mitigating oxidative stress. The activity of antioxidant enzymes enhanced under Cd treatment and AMF inoculation further enhanced their activity, thus strengthening the plant's defense system. Proline and phenol content increased in Cd-treated as well as AMF-inoculated plants providing efficient protection against Cd stress. Cadmium treatment resulted in great alterations in the main lipid classes leading to a marked change in their composition. Cadmium stress caused a significant reduction in polyunsaturated fatty acids resulting in enhanced membrane leakage. The present study supports the use of AMF as a biological means to ameliorate Cd stress-induced changes in tomato. PMID:26981010

  3. Reduction of Cadmium Uptake of Rice Plants Using Soil Amendments in High Cadmium Contaminated Soil: A Pot Experiment

    Directory of Open Access Journals (Sweden)

    Dian Siswanto

    2013-05-01

    Full Text Available The aims of this study were to investigate the effect of agricultural residues on reducing cadmium uptake in rice plants. The rice plants growing on no cadmium/free cadmium soils (N, Cd soils (Cds, and Cd soils each amended with 1% w/w of coir pith (CP, coir pith modified with sodium hydroxide (CPm and corncob (CC under high cadmium contaminated soil with an average 145 mg Cd kg-1 soil were investigated. The results showed that the cumulative transpiration of rice grown in various treatments under high cadmium contaminated soil followed the order: Cds > CPm ≥ CP ≥ CC. These transpirations directly influenced cadmium accumulation in shoots and husks of rice plants. The CC and CP seemed to work to reduce the cadmium uptake by rice plants indicated by accumulated cadmium in the husk that were 2.47 and 7.38 mg Cd kg-1 dry weight, respectively. Overall, transpiration tended to drive cadmium accumulation in plants for rice grown in high cadmium contaminated soil. The more that plants uptake cadmium, the lower cadmium that remains in the soil.

  4. Bireactor Electronuclear Systems with Liquid Cadmium Valve

    CERN Document Server

    Bznuni, S A; Zhamkochyan, V M; ASosnin, A N; Polanski, A; Khudaverdyan, A H

    2002-01-01

    Three main types of bireactor electronuclear systems are discussed. From the point of view of assuring high level of functional characteristics and safety bireactor electronuclear systems with booster using enriched uranium (20 %) and with a liquid cadmium valve appears to be the most effective. It is shown by means of Monte-Carlo modeling that such operation conditions can be achieved which lead to the destruction of the intermediate cadmium layer making the systems supercritical (k_{eff}>1). One can avoid the problem by using a special design of the liquid cadmium valve. In comparison with other nuclear systems (critical reactors, one-reactor electronuclear systems) cascade electronuclear systems have essential advantages allowing the decrease of the proton beam current by one order of magnitude and providing at same time the necessary level of power generation and neutron flux. Availability of both the thermal and fast cones allows one to transmute not only transuranics but also the fission products - cesi...

  5. ELECTROKINETIC REMEDIATION STUDY FOR CADMIUM CONTAMINATED SOIL

    Directory of Open Access Journals (Sweden)

    P. Bala Ramudu

    2007-09-01

    Full Text Available This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself was used as the purging solution. Results showed that 49% reduction of cadmium concentration was achieved in the case of soil saturated (washed with ammonium citrate as well as purging solution also was ammonium citrate. The soil pH and washing solutions were the most important factors in controlling the removal of cadmium in electrokinetic remediation process.

  6. Increased cadmium and lead uptake of a cadmium hyperaccumulator tomato by cadmium-resistant bacteria.

    Science.gov (United States)

    He, Lin-Yan; Chen, Zhao-Jin; Ren, Gai-Di; Zhang, Yan-Feng; Qian, Meng; Sheng, Xia-Fang

    2009-07-01

    Two cadmium (Cd)-resistant strains Pseudomonas sp. RJ10 and Bacillus sp. RJ16 were investigated for their effects on the soil Cd and lead (Pb) solubilization and promotion of plant growth and Cd and Pb uptakes of a Cd-hyperaccumulator tomato. In the heavy metal-contaminated inoculated soil, the CaCl(2)-extractable Cd and Pb were increased by 58-104% and 67-93%, respectively, compared to the uninoculation control. The bacteria produced indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase. Root elongation assay conducted on tomato under gnotobiotic conditions demonstrated increase in root elongation of inoculated tomato seedlings compared to the control plants. An increase in Cd and Pb contents of above-ground tissues varied from 92% to 113% and from 73% to 79% in inoculated plants growing in heavy metal-contaminated soil compared to the uninoculation control, respectively. These results show that the bacteria could be exploited for bacteria enhanced-phytoextraction of Cd- and Pb-polluted soils. PMID:19368973

  7. Treatment of cadmium dust with two-stage leaching process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The treatment of cadmium dust with a two-stage leaching process was investigated to replace the existing sulphation roast-leaching processes. The process parameters in the first stage leaching were basically similar to the neutralleaching in zinc hydrometallurgy. The effects of process parameters in the second stage leaching on the extraction of zincand cadmium were mainly studied. The experimental results indicated that zinc and cadmium could be efficiently recoveredfrom the cadmium dust by two-stage leaching process. The extraction percentages of zinc and cadmium in two stage leach-ing reached 95% and 88% respectively under the optimum conditions. The total extraction percentage of Zn and Cdreached 94%.

  8. Cadmium toxicity in the free-living nematode, Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Popham, J.D.; Webster, J.M.

    1979-10-01

    The effect of cadmium on the fecundity, growth, and fine structure of the free-living nematode Caenorhabditis elegans was studied. High concentrations of cadmium significantly decreased the fecundity and growth of these organisms. Electron microscopy showed that cadmium modifies the structure of the mitochondria in the esophagus and intestine, causes the formation of inclusion bodies in the nucleus of esophageal cells, and alters the morphology of cytosomes in the intestinal cells. The results suggest that the decreased fecundity and growth of cadmium-exposed C. elegans may be due to cadmium interfering with nutrient uptake or assimilation or both.

  9. Thermodynamic properties of cadmium in lead amalgam dilute solution

    International Nuclear Information System (INIS)

    Investigation of thermodynamic properties of cadmium dilute solutions in lead amalgam is carried out by means of electromotive force technique within 453-523 K temperature range. Cadmium thermodynamic functions are calculated: activity, activity ratio, Libbs partial energy and its excess value and integral characteristics, respectively. When changing cadmium content from 0.01 up to 0.1 χcd at T=473 K, logarithm of activity ratio does not depend on alloy composition, that is, Heury's law is fulfilled. Increase of cadmium content in amalgam results in the essential reduction of mercury and cadmium reaction

  10. Urinary excretion of cadmium and zinc among persons from Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.G.; Kjellstrom, T.; Linnman, L.; Pershagen, G.

    1978-06-01

    Cadmium and zinc concentrations in the urine of 132 Swedes, including 50 pairs of identical twins, were measured. Atomic absorption spectrophotometry procedures were developed for the analysis. Cadmium concentration increased with age and was higher among smokers than among nonsmokers. Estimated 24-hr excretion of cadmium among nonsmokers increased from about 0.25 to 0.40 ..mu..g in persons from 20 to 70 years old. The 24-hr cadmium excretions among nonsmokers in different age-groups fitted better to total kidney burden than to daily cadmium intake from food. Zinc excretion, on the other hand, decreased after the age of 20.

  11. Cadmium telluride quantum dots advances and applications

    CERN Document Server

    Donegan, John

    2013-01-01

    Optical Properties of Bulk and Nanocrystalline Cadmium Telluride, Núñez Fernández and M.I. VasilevskiyAqueous Synthesis of Colloidal CdTe Nanocrystals, V. Lesnyak, N. Gaponik, and A. EychmüllerAssemblies of Thiol-Capped CdTe Nanocrystals, N. GaponikFörster Resonant Energy Transfer in CdTe Nanocrystal Quantum Dot Structures, M. Lunz and A.L. BradleyEmission of CdTe Nanocrystals Coupled to Microcavities, Y.P. Rakovich and J.F. DoneganBiological Applications of Cadmium Telluride Semiconductor Quantum Dots, A. Le Cign

  12. Elektrokemisk fjernelse af cadmium fra bioasker

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter;

    Posteren viser resultater fra elektrokemiske rensningsforsøg på bioasker udført i forbindelse med PSO projekt 5205 "Elektrokemisk fjernelse af cadmium fra bioasker i pilotskala og vurdering af mulighederne for nyttiggørelse af behandlet aske i beton".......Posteren viser resultater fra elektrokemiske rensningsforsøg på bioasker udført i forbindelse med PSO projekt 5205 "Elektrokemisk fjernelse af cadmium fra bioasker i pilotskala og vurdering af mulighederne for nyttiggørelse af behandlet aske i beton"....

  13. Evaluation of phosphate fertilizers for the stabilization of cadmium in highly contaminated soils.

    Science.gov (United States)

    Thawornchaisit, Usarat; Polprasert, Chongrak

    2009-06-15

    The efficiency of three phosphate fertilizers including triple superphosphate (TSP), diammonium phosphate (DAP), and phosphate rock (PR) as stabilizing agents of cadmium-contaminated soils has been assessed in this study. Two types of assessment criteria, (a) the reduction of leachable cadmium concentration; and (b) the changes in Cd association with specific operational soil fraction based on the sequential extraction data, are used in the evaluation of stabilization performance of each fertilizer. Results of the study showed that after the 60-day stabilization, the leachable concentrations of Cd in PR-, DAP- and TSP- treated soils reduced from 306 mg/kg (the control) to 140, 34, and 12 mg/kg with the stabilization efficiency as TSP>DAP>PR. Results from the assessment of Cd speciation via sequential extraction procedure revealed that the soluble-exchangeable fraction and the surface adsorption fraction of Cd in the soils treated with PO(4) fertilizers, especially with TSP, have been reduced considerably. In addition, it is found that the reduction was correspondingly related with the increase of more stable forms of cadmium: the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (based on the molar ratio of PO(4)/Cd) increased. In addition, it was observed that stabilization was most effective when using the molar ratio of PO(4)/Cd at 2:1 and at least 21-day and 28-day stabilization time for TSP and DAP, respectively. PMID:19118949

  14. Evaluation of phosphate fertilizers for the stabilization of cadmium in highly contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Thawornchaisit, Usarat, E-mail: kpusarat@kmitl.ac.th [Department of Chemistry, Faculty of Science, King Mongkut' s Institute of Technology Ladkrabang (KMITL), Chalongkrung Road, Ladkrabang, Bangkok 10520 (Thailand); Polprasert, Chongrak, E-mail: chongrak@ait.ac.th [Environmental Engineering and Management, School of Environment, Resources and Development, Asian Institute of Technology (AIT), P.O. Box 4, Klong Luang, Pathumthani 12120 (Thailand)

    2009-06-15

    The efficiency of three phosphate fertilizers including triple superphosphate (TSP), diammonium phosphate (DAP), and phosphate rock (PR) as stabilizing agents of cadmium-contaminated soils has been assessed in this study. Two types of assessment criteria, (a) the reduction of leachable cadmium concentration; and (b) the changes in Cd association with specific operational soil fraction based on the sequential extraction data, are used in the evaluation of stabilization performance of each fertilizer. Results of the study showed that after the 60-day stabilization, the leachable concentrations of Cd in PR-, DAP- and TSP- treated soils reduced from 306 mg/kg (the control) to 140, 34, and 12 mg/kg with the stabilization efficiency as TSP>DAP>PR. Results from the assessment of Cd speciation via sequential extraction procedure revealed that the soluble-exchangeable fraction and the surface adsorption fraction of Cd in the soils treated with PO{sub 4} fertilizers, especially with TSP, have been reduced considerably. In addition, it is found that the reduction was correspondingly related with the increase of more stable forms of cadmium: the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (based on the molar ratio of PO{sub 4}/Cd) increased. In addition, it was observed that stabilization was most effective when using the molar ratio of PO{sub 4}/Cd at 2:1 and at least 21-day and 28-day stabilization time for TSP and DAP, respectively.

  15. Evaluation of phosphate fertilizers for the stabilization of cadmium in highly contaminated soils.

    Science.gov (United States)

    Thawornchaisit, Usarat; Polprasert, Chongrak

    2009-06-15

    The efficiency of three phosphate fertilizers including triple superphosphate (TSP), diammonium phosphate (DAP), and phosphate rock (PR) as stabilizing agents of cadmium-contaminated soils has been assessed in this study. Two types of assessment criteria, (a) the reduction of leachable cadmium concentration; and (b) the changes in Cd association with specific operational soil fraction based on the sequential extraction data, are used in the evaluation of stabilization performance of each fertilizer. Results of the study showed that after the 60-day stabilization, the leachable concentrations of Cd in PR-, DAP- and TSP- treated soils reduced from 306 mg/kg (the control) to 140, 34, and 12 mg/kg with the stabilization efficiency as TSP>DAP>PR. Results from the assessment of Cd speciation via sequential extraction procedure revealed that the soluble-exchangeable fraction and the surface adsorption fraction of Cd in the soils treated with PO(4) fertilizers, especially with TSP, have been reduced considerably. In addition, it is found that the reduction was correspondingly related with the increase of more stable forms of cadmium: the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (based on the molar ratio of PO(4)/Cd) increased. In addition, it was observed that stabilization was most effective when using the molar ratio of PO(4)/Cd at 2:1 and at least 21-day and 28-day stabilization time for TSP and DAP, respectively.

  16. Evaluation of phosphate fertilizers for the stabilization of cadmium in highly contaminated soils

    International Nuclear Information System (INIS)

    The efficiency of three phosphate fertilizers including triple superphosphate (TSP), diammonium phosphate (DAP), and phosphate rock (PR) as stabilizing agents of cadmium-contaminated soils has been assessed in this study. Two types of assessment criteria, (a) the reduction of leachable cadmium concentration; and (b) the changes in Cd association with specific operational soil fraction based on the sequential extraction data, are used in the evaluation of stabilization performance of each fertilizer. Results of the study showed that after the 60-day stabilization, the leachable concentrations of Cd in PR-, DAP- and TSP- treated soils reduced from 306 mg/kg (the control) to 140, 34, and 12 mg/kg with the stabilization efficiency as TSP>DAP>PR. Results from the assessment of Cd speciation via sequential extraction procedure revealed that the soluble-exchangeable fraction and the surface adsorption fraction of Cd in the soils treated with PO4 fertilizers, especially with TSP, have been reduced considerably. In addition, it is found that the reduction was correspondingly related with the increase of more stable forms of cadmium: the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (based on the molar ratio of PO4/Cd) increased. In addition, it was observed that stabilization was most effective when using the molar ratio of PO4/Cd at 2:1 and at least 21-day and 28-day stabilization time for TSP and DAP, respectively.

  17. Cadmium exposure and pancreatic cancer in south Louisiana.

    Science.gov (United States)

    Luckett, Brian G; Su, L Joseph; Rood, Jennifer C; Fontham, Elizabeth T H

    2012-01-01

    Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana). We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney cortex. Increasing urinary cadmium concentrations were significantly associated with an increasing risk of pancreatic cancer (2nd quartile OR = 3.34, 3rd = 5.58, 4th = 7.70; test for trend P ≤ 0.0001). Potential sources of cadmium exposure, as documented in the scientific literature, found to be statistically significantly associated with increased risk of pancreatic cancer included working as a plumber, pipefitter or welder (OR = 5.88) and high consumption levels of red meat (4th quartile OR = 6.18) and grains (4th quartile OR = 3.38). Current cigarette smoking, at least 80 pack years of smoking, occupational exposure to cadmium and paints, working in a shipyard, and high consumption of grains were found to be statistically significantly associated with increased concentrations of urinary cadmium. This study provides epidemiologic evidence that cadmium is a potential human pancreatic carcinogen. PMID:23319964

  18. Cadmium Exposure and Pancreatic Cancer in South Louisiana

    Directory of Open Access Journals (Sweden)

    Brian G. Luckett

    2012-01-01

    Full Text Available Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana. We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney cortex. Increasing urinary cadmium concentrations were significantly associated with an increasing risk of pancreatic cancer (2nd quartile OR = 3.34, 3rd = 5.58, 4th = 7.70; test for trend P≤0.0001. Potential sources of cadmium exposure, as documented in the scientific literature, found to be statistically significantly associated with increased risk of pancreatic cancer included working as a plumber, pipefitter or welder (OR = 5.88 and high consumption levels of red meat (4th quartile OR = 6.18 and grains (4th quartile OR = 3.38. Current cigarette smoking, at least 80 pack years of smoking, occupational exposure to cadmium and paints, working in a shipyard, and high consumption of grains were found to be statistically significantly associated with increased concentrations of urinary cadmium. This study provides epidemiologic evidence that cadmium is a potential human pancreatic carcinogen.

  19. Selection and breeding of plant cultivars to minimize cadmium accumulation

    International Nuclear Information System (INIS)

    Natural variation occurs in the uptake and distribution of essential and nonessential trace elements among crop species and among cultivars within species. Such variation can be responsible for trace element deficiencies and toxicities, which in turn can affect the quality of food. Plant breeding can be an important tool to both increase the concentration of desirable trace elements and reduce that of potentially harmful trace elements such as cadmium (Cd). Selection programs for a low-Cd content of various crops, including durum wheat, sunflower, rice and soybean have been established and low-Cd durum wheat cultivars and sunflower hybrids have been developed. In durum wheat (Triticum turgidum L. var durum), low-Cd concentration is controlled by a single dominant gene. The trait is highly heritable, and incorporation of the low-Cd allele can help to reduce the average grain Cd to levels below proposed international limits. The allele for low-Cd concentration does not appear to affect major economic traits and should not cause problems when incorporated into durum cultivars. The cost of Cd selection in a breeding program is initially large both in terms of Cd determination and reduced progress towards development of other economic traits, but declines as more breeding lines in the program carry the low-Cd trait and are utilized in new crosses. Production of low-Cd crop cultivars can be used as a tool to reduce the risk of movement of Cd into the human diet

  20. Study of cadmium electrochemical deposition in sulfate medium

    Energy Technology Data Exchange (ETDEWEB)

    Montiel, T.; Solorza, O.; Sanchez, H.

    2000-03-01

    The cadmium electrochemical deposition process from sulfate medium was studied by means of different electrochemical techniques in both stationary and nonstationary diffusion regimes. The kinetics of the electrochemical reduction of cadmium on solid cadmium electrodes was examined and the kinetic parameters are presented, as well as the diffusion coefficient derived from the different techniques. Temperature has an important effect on the cadmium reduction kinetics, and the activation energy of the process was evaluated. The electrochemical deposition of cadmium is a complex process due to the coexistence of adsorption and nucleation processes; the adsorbed electroactive species appears to be Cd{sup +2}, and a mechanism for cadmium electrodeposition on solid cadmium electrodes is proposed.

  1. Murine strain differences and the effects of zinc on cadmium concentrations in tissues after acute cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    King, L.M. [ARS USDA, Germplasm and Gamete Physiology Lab., Beltsville, MD (United States); Anderson, M.B. [Dept. of Anatomy, Tulane Univ. School of Medicine, New Orleans, LA (United States); Sikka, S.C. [Dept. of Urology, Tulane Univ. School of Medicine, New Orleans, LA (United States); George, W.J. [Dept. of Pharmacology, Tulane Univ. School of Medicine, New Orleans, LA (United States)

    1998-10-01

    The role of strain differences in cadmium tissue distribution was studied using sensitive (129/J) and resistant (A/J) mice. These murine strains have previously been shown to differ in their susceptibility to cadmium-induced testicular toxicity. Cadmium concentration was measured in testis, epididymis, seminal vesicle, liver, and kidney at 24 h after cadmium chloride exposure (4, 10, and 20 {mu}mol/kg CdCl{sub 2}). The 129/J mice exhibited a significant increase in cadmium concentration in testis, epididymis, and seminal vesicle at all cadmium doses used, compared to A/J mice. However, cadmium concentrations in liver and kidney were not different between the strains, at any dose, indicating that cadmium uptake is similar in these organs at 24 h. These murine strains demonstrate similar hepatic and renal cadmium uptake but significantly different cadmium accumulation in the reproductive organs at 24 h. The mechanism of the protective effect of zinc on cadmium toxicity was studied by assessing the impact of zinc acetate (ZnAc) treatment on cadmium concentrations in 129/J mice after 24 h. Zinc pretreatment (250 {mu}mol/kg ZnAc), given 24 h prior to 20 {mu}mol/kg CdCl{sub 2} administration, significantly decreased the amount of cadmium in the testis, epididymis, and seminal vesicle of 129/J mice, and significantly increased the cadmium content of the liver after 24 h. Cadmium levels in the kidney were unaffected at this time. Zinc pretreatment also prevented the cadmium-induced decrease in testicular sperm concentration and epididymal sperm motility seen in 129/J mice. These findings suggest that the differences in the two murine strains may be attributed partly to the differential accumulation of cadmium in murine gonads. This may be caused by strain differences in the specificity of cadmium transport mechanisms. The protective role of zinc in cadmium-induced testicular toxicity in the sensitive strain may be due to an interference in the cadmium uptake by susceptible

  2. Kinetics of cadmium uptake by chitosan-based crab shells.

    Science.gov (United States)

    Evans, Johanna R; Davids, William G; MacRae, Jean D; Amirbahman, Aria

    2002-07-01

    Crushed crab shells were chemically treated to transform the chitin present into chitosan. Three particle sizes with average diameters of 0.65, 1.43 and 3.38 mm, average pore diameters ranging from approximately 300 to 540 A, and a specific surface area of approximately 30 m2/g were obtained. Batch experiments were performed to study the uptake equilibrium and kinetics of cadmium by chitosan. Adsorption equilibrium followed a Freundlich relationship and was found to be independent of particle size indicating that adsorption takes place largely in the pore space. A high initial rate of cadmium uptake was followed by a slower uptake rate suggesting intraparticle diffusion as the rate-limiting step. The kinetic uptake data were successfully modeled using a pore diffusion model incorporating nonlinear adsorption. The effect of boundary layer resistance was modeled through inclusion of a mass transfer expression at the outside boundary. Two fitting parameters, the tortuosity factor (tau) and the mass transfer coefficient at the outside boundary (k(c)) were used. These parameters were unique for all solute and sorbent concentrations. The tortuosity factors varied from 1.5 for large particles to 5.1 for small particles. The mass transfer coefficient varied from 2 x 10(-7) m/s at 50 rpm to 2 x 10(-3) m/s at 200 rpm. At agitation rates below 100 rpm, boundary layer resistance reduced the uptake rate significantly. Its very high sorption capacity and relatively low production cost make chitosan an attractive sorbent for the removal of heavy metals from waste streams.

  3. Protective effect of Tribulus terrestris linn on liver and kidney in cadmium intoxicated rats.

    Science.gov (United States)

    Lakshmi, G Dhana; Kumar, P Ravi; Bharavi, K; Annapurna, P; Rajendar, B; Patel, Pankaj T; Kumar, C S V Satish; Rao, G S

    2012-02-01

    Administration of cadmium (Cd) significantly increased the peroxidation markers such as malondialdehyde and protein carbonyls along with significant decrease in antioxidant markers such as super oxide dismutase and reduced glutathione in liver and kidney tissues. Cadmium also caused a significant alteration in hepatic and renal functional markers in serum viz. total protein, albumin, alanine transaminase, blood urea nitrogen and creatinine. Prominent pathological changes observed in liver were severe vascular and sinusoidal congestion with diffuse degenerative changes and mononuclear infiltration into peripheral areas, while the kidney showed vascular and glomerular congestion, cloudy swelling of tubular epithelium. Coadministration of ethonolic extract of T. terrestris or vitamin E along with Cd significantly reversed the Cd induced changes along with significant reduction in Cd load. PMID:22670477

  4. Urinary cadmium and estimated dietary cadmium in the Women's Health Initiative.

    Science.gov (United States)

    Quraishi, Sabah M; Adams, Scott V; Shafer, Martin; Meliker, Jaymie R; Li, Wenjun; Luo, Juhua; Neuhouser, Marian L; Newcomb, Polly A

    2016-01-01

    Cadmium, a heavy metal dispersed in the environment as a result of industrial and agricultural applications, has been implicated in several human diseases including renal disease, cancers, and compromised bone health. In the general population, the predominant sources of cadmium exposure are tobacco and diet. Urinary cadmium (uCd) reflects long-term exposure and has been frequently used to assess cadmium exposure in epidemiological studies; estimated dietary intake of cadmium (dCd) has also been used in several studies. The validity of dCd in comparison with uCd is unclear. This study aimed to compare dCd, estimated from food frequency questionnaires, to uCd measured in spot urine samples from 1,002 participants of the Women's Health Initiative. Using linear regression, we found that dCd was not statistically significantly associated with uCd (β=0.006, P-value=0.14). When stratified by smoking status, dCd was not significantly associated with uCd both in never smokers (β=0.006, P-value=0.09) and in ever smokers (β=0.003, P-value=0.67). Our results suggest that because of the lack of association between estimated dCd and measured uCd, dietary estimation of cadmium exposure should be used with caution in epidemiologic studies.

  5. Metabolic profiling detects early effects of environmental and lifestyle exposure to cadmium in a human population

    Directory of Open Access Journals (Sweden)

    Ellis James K

    2012-06-01

    Full Text Available Abstract Background The 'exposome' represents the accumulation of all environmental exposures across a lifetime. Top-down strategies are required to assess something this comprehensive, and could transform our understanding of how environmental factors affect human health. Metabolic profiling (metabonomics/metabolomics defines an individual's metabolic phenotype, which is influenced by genotype, diet, lifestyle, health and xenobiotic exposure, and could also reveal intermediate biomarkers for disease risk that reflect adaptive response to exposure. We investigated changes in metabolism in volunteers living near a point source of environmental pollution: a closed zinc smelter with associated elevated levels of environmental cadmium. Methods High-resolution 1H NMR spectroscopy (metabonomics was used to acquire urinary metabolic profiles from 178 human volunteers. The spectral data were subjected to multivariate and univariate analysis to identify metabolites that were correlated with lifestyle or biological factors. Urinary levels of 8-oxo-deoxyguanosine were also measured, using mass spectrometry, as a marker of systemic oxidative stress. Results Six urinary metabolites, either associated with mitochondrial metabolism (citrate, 3-hydroxyisovalerate, 4-deoxy-erythronic acid or one-carbon metabolism (dimethylglycine, creatinine, creatine, were associated with cadmium exposure. In particular, citrate levels retained a significant correlation to urinary cadmium and smoking status after controlling for age and sex. Oxidative stress (as determined by urinary 8-oxo-deoxyguanosine levels was elevated in individuals with high cadmium exposure, supporting the hypothesis that heavy metal accumulation was causing mitochondrial dysfunction. Conclusions This study shows evidence that an NMR-based metabolic profiling study in an uncontrolled human population is capable of identifying intermediate biomarkers of response to toxicants at true environmental

  6. RISK ASSESSMENT FOR CADMIUM IN PHOSPHATE FERTILIZERS

    Science.gov (United States)

    Cadmium induced renal tubular dysfunction occurred where subsistence rice farmers produced their lifetime dietary rice on Zn-mine waste contaminated soils in Japan and other Asian countries. Research has shown that polished rice Cd is greatly increased while grain Zn is not incre...

  7. Field scale behaviour of cadmium in soil.

    NARCIS (Netherlands)

    Boekhold, A.E.

    1992-01-01

    Although total heavy metal contents of soil are often used to express the degree of contamination, they are of little value to judge environmental effects. The main objective of this thesis was to develop and test methodologies with which environmental risks of cadmium pollution of field soils can b

  8. Mobiliteit van cadmium in de bodem

    NARCIS (Netherlands)

    Chardon, W.J.

    1984-01-01

    The adsorption of cadmium by twelve Dutch soils was investigated under widely varying circumstances. The adsorption can be described with the Freundlich equation; the parameters of this equation can be predicted using the properties of the soil (pH, organic carbon and clay content).The adsorption ap

  9. Cadmium isotope variations in the Southern Ocean

    NARCIS (Netherlands)

    Xue, Z.; Rehkämper, M.; Horner, T.J.; Abouchami, W.; Middag, R.; van de Flierd, T.; de Baar, H.J.W.

    2013-01-01

    Cadmium concentrations and isotope compositions were determined for 47 seawater samples from the high nutrient low chlorophyll (HNLC) zone of the Atlantic sector of the Southern Ocean. The samples include 13 surface waters from a transect of the Weddell Gyre and 3 depth profiles from the Weddell Sea

  10. Cadmium phytoextraction potential of different Alyssum species

    Energy Technology Data Exchange (ETDEWEB)

    Barzanti, R., E-mail: rbarzanti@supereva.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Colzi, I., E-mail: ilariacolzi@hotmail.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Arnetoli, M., E-mail: miluscia@gmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gallo, A., E-mail: galloalessia@hotmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Pignattelli, S., E-mail: sara.pignattelli@gmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gabbrielli, R., E-mail: gabbrielli@unifi.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gonnelli, C., E-mail: cristina.gonnelli@unifi.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer The possibility of using serpentine plants for phytoextraction of Cd was investigated. Black-Right-Pointing-Pointer Variation in Cd tolerance, accumulation and translocation in three Alyssum plants with different phenotypes were found. Black-Right-Pointing-Pointer Alyssum montanum showed higher Cd tolerance and accumulation than the Ni hyperaccumulator Alyssum bertolonii. Black-Right-Pointing-Pointer As for the kinetic parameters of the Cd uptake system, A. montanum presented a low apparent K{sub m} value. Black-Right-Pointing-Pointer The V{sub max} values were not significantly different among the plants. - Abstract: This work was planned for providing useful information about the possibility of using serpentine adapted plants for phytoextraction of cadmium, element scarcely represented in such metalliferous environment. To this aim, we investigated variation in cadmium tolerance, accumulation and translocation in three Alyssum plants with different phenotypes: Alyssum bertolonii, that is a serpentine endemic nickel hyperaccumulator, and two populations of Alyssum montanum, one adapted and one not adapted to serpentine soils. Plants were hydroponically cultivated in presence of increasing concentrations of CdSO{sub 4} for two weeks. For the metal concentration used in the experiments, the three different Alyssum populations showed variation in cadmium tolerance, accumulation and content. The serpentine adapted population of A. montanum showed statistically higher cadmium tolerance and accumulation than A. bertolonii and the population of A. montanum not adapted to serpentine soil thus deserving to be investigated for phytoextraction purposes. Furthermore, as for the kinetic parameters of the cadmium uptake system, A. montanum serpentine population presented a low apparent K{sub m} value, suggesting a high affinity for this metal of its uptake system, whereas the V{sub max} values were not significantly different among the

  11. Cadmium and Chrome Concentrations in Human Milk

    Directory of Open Access Journals (Sweden)

    Sima Nazarpour

    2014-04-01

    Full Text Available Introduction: Nutrition of children has the highest priority in any program aimed at children's health care. Milk contaminated with various toxic elements can have adverse effects on children's health. This study aimed to determine the concentration of heavy metals including cadmium(Cd and chromium (Cr of breast feeding women’s milk in Varamin. Methods: This is a cross sectional study. In the present study, chromium and cadmium levels in milk of 100 mothers attending clinics in the city of Varamin were measured in four to eight weeks after delivery, using atomic absorption spectrometry. Results: The mean values (±SD of Cd and Cr in human milk were 5±6.9 μg/ml and 3±2.7 μg/ml respectively. Result of Linear regression showed that cadmium levels were higher in breast milk of people living close to the factory or industrial center. Also, the chromium levels were higher in the breast milk of women in cases of: Smoking by spouses, consumption of imported rice, consumption of mineral water, and living close to the factory or an industrial center. Conclusion: This study showed that the relationship of some factors such as living near a factory or an industrial center, smoking by spouse, the type of consumed rice and water, with the level of cadmium and chromium. Cadmium and chromium levels of breast milk in this study were higher than the levels of these elements mentioned in the reviewed articles and international standard. Because some variables, such as living near a factory or an industrial center, smoking by spouse, the type of consumed rice and water can affect the amount of entering elements in breast milk. Actions can be taken to reduce or eliminate these variables in order to decrease the mentioned elements in human milk.

  12. Modelling of Cadmium Transport in Soil-Crop System

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A model for simulating cadmium transport in a soil-plant system was built using a commercial simu lating program named Powersim on the basis of input-output processes happening in the soil-plant system.Convective and dispersive transport processes of cadmium in soil profile are embedded. Simulations on a daily base have been done up to a total simulating time of 250 years. Results show that applications of sewage sludge and fertilizer at the simulated rates would only cause slight cadmium accumulations in each layer of the soil, and cadmium accumulation would be levelling off, reaching an equilibrium concentrations layer by layer downward after certain time. The time scale to reach an equilibrium concentration varies from 10 years for the top three layers to over 250 years for the bottom layers. Plant cadmium uptake would increase from 52 ug m-2 under initial soil cadmium concentrations to 65 μg m-2 under equilibrium soil cadmium concentrations, which would not exceed the maximum allowable cadmium concentration in wheat grains. Main parameters which influence cadmium accumulation and transport in soil are total cadmium input, rainfall, evaporation, plant uptake and soil properties.

  13. Suitability of Cadmium Tantalate and Indium Tantalate as Control Materials for High-Temperature Reactors

    International Nuclear Information System (INIS)

    Control materials for practical use in high-temperature reactors should, independently of the requirements of the individual case, have the following properties: (a ) high absorption cross-section for neutrons in a wide range of energies; (b ) high absorption capacity for neutrons; (c ) small sensitivity for radiation damage; (d) good thermal resistance; (e ) low reactivity with the environment; and ( f ) low costs and good availability. With these points and the avoidance of the disadvantages of n, α -reactions taken into consideration, attention should be paid chiefly to the elements cadmium, tungsten, indium and tantalum. It is important to combine a good thermal absorber with an epithermál absorber so that the resulting material is stable at elevated temperatures (≳ 700°C). For this purpose the double-oxides CdWO4, Cd 2Ta2O7 and CdIn2O2 are suitable. Among these, cadmium tantalate has the highest thermal resistance. Another double-oxide which in combination with cadmium tantalate possesses an advantageous absorption spectrum for neutrons is indium tantalate. It has also good thermal resistance. Because ceramic absorber materials often have to be shaped by plastic deformation, they usually are used as cermets. Therefore, they must be compatible with metals. Cadmium tantalate is compatible with silver and copper and up to 700°C with nickel; indium, tantalate is completely compatible with silver, copper and nickel and up to 700°C with molybdenum also and to some degree with iron. These results are in agreement with thermodynamical calculations. For an estimation of the behaviour of the absorber materials under reactor conditions the daughter products originating from neutron absorption have to be considered. While Cd113 transforms into the stable Cd114, tantalum transmutes into tungsten and indium into tin. Both daughter products can bind more oxygen in their most stable valency states than the parent elements can. Therefore, the reduction of Cd++to metal

  14. Nepal CRS project incorporates.

    Science.gov (United States)

    1983-01-01

    The Nepal Contraceptive Retail Sales (CRS) Project, 5 years after lauching product sales in June 1978, incorporated as a private, nonprofit company under Nepalese management. The transition was finalized in August 1983. The Company will work through a cooperative agreement with USAID/Kathmandu to complement the national family planning goals as the program continues to provide comtraceptives through retail channels at subsidized prices. Company objectives include: increase contraceptive sales by at least 15% per year; make CRS cost effective and move towards self sufficiency; and explore the possibility of marketing noncontraceptive health products to improve primary health care. After only5 years the program can point to some impressive successes. The number of retial shops selling family planning products increased from 100 in 1978 to over 8000, extending CRS product availability to 66 of the country's 75 districts. Retail sales have climbed dramatically in the 5-year period, from Rs 46,817 in 1978 to Rs 271,039 in 1982. Sales in terms of couple year protection CYP) have grown to 24,451 CYP(1982), a 36% increase over 1980 CYP. Since the beginning of the CRS marketing program, total distribution of contraceptives--through both CRS and the Family Planning Maternal and Child Haelth (FP/MCH) Project--has been increasing. While the FP/MCH program remains the largest distributor,contribution of CRS Products is increasing, indicating that CRS is creating new product acceptors. CRS market share in 1982 was 43% for condoms and 16% for oral contraceptives (OCs). CRS markets 5 products which are subsidized in order to be affordable to consumers as well as attractive to sellers. The initial products launched in June 1978 were Gulaf standard dose OCs and Dhaal lubricated colored condoms. A less expensive lubricates, plain Suki-Dhaal condom was introduced in June 1980 in an attempt to reach poorer rural populations, but rural distribution costs are excessive and Suki

  15. Nepal CRS project incorporates.

    Science.gov (United States)

    1983-01-01

    The Nepal Contraceptive Retail Sales (CRS) Project, 5 years after lauching product sales in June 1978, incorporated as a private, nonprofit company under Nepalese management. The transition was finalized in August 1983. The Company will work through a cooperative agreement with USAID/Kathmandu to complement the national family planning goals as the program continues to provide comtraceptives through retail channels at subsidized prices. Company objectives include: increase contraceptive sales by at least 15% per year; make CRS cost effective and move towards self sufficiency; and explore the possibility of marketing noncontraceptive health products to improve primary health care. After only5 years the program can point to some impressive successes. The number of retial shops selling family planning products increased from 100 in 1978 to over 8000, extending CRS product availability to 66 of the country's 75 districts. Retail sales have climbed dramatically in the 5-year period, from Rs 46,817 in 1978 to Rs 271,039 in 1982. Sales in terms of couple year protection CYP) have grown to 24,451 CYP(1982), a 36% increase over 1980 CYP. Since the beginning of the CRS marketing program, total distribution of contraceptives--through both CRS and the Family Planning Maternal and Child Haelth (FP/MCH) Project--has been increasing. While the FP/MCH program remains the largest distributor,contribution of CRS Products is increasing, indicating that CRS is creating new product acceptors. CRS market share in 1982 was 43% for condoms and 16% for oral contraceptives (OCs). CRS markets 5 products which are subsidized in order to be affordable to consumers as well as attractive to sellers. The initial products launched in June 1978 were Gulaf standard dose OCs and Dhaal lubricated colored condoms. A less expensive lubricates, plain Suki-Dhaal condom was introduced in June 1980 in an attempt to reach poorer rural populations, but rural distribution costs are excessive and Suki

  16. High efficiency indium oxide/cadmium telluride solar cells

    Science.gov (United States)

    Nakazawa, T.; Takamizawa, K.; Ito, K.

    1987-02-01

    Solar cells have been fabricated by reactive deposition of thin-film n-In2O3 onto single-crystal p-CdTe. The cell has a total area solar power conversion efficiency of 13.4 percent which corresponds to an active area efficiency of 14.4 percent at air mass 1.5 without antireflection coatings. The cell consists of a buried homojunction structure with low dark saturation current density.

  17. Mixed-chelate therapy of intratracheally deposited cadmium oxide

    International Nuclear Information System (INIS)

    Mixed-chelate treatment with EDTA and salicylic acid was no more effective in accelerating the removal of intratracheally instilled 109CdO, or in protecting against CdO-induced mortality, than was EDTA given alone

  18. Contribution of phytochelatins to cadmium tolerance in peanut plants.

    Science.gov (United States)

    Bianucci, Eliana; Sobrino-Plata, Juan; Carpena-Ruiz, Ramón O; Del Carmen Tordable, María; Fabra, Adriana; Hernández, Luis E; Castro, Stella

    2012-10-01

    Cadmium (Cd) is a well known heavy metal considered as one of the most toxic metals on Earth, affecting all viable cells that are exposed even at low concentration. It is introduced to agricultural soils mainly by phosphate fertilizers and causes many toxic symptoms in cells. Phytochelatins (PCs) are non-protein thiols which are involved in oxidative stress protection and are strongly induced by Cd. In this work, we analyzed metal toxicity as well as PCs implication on protection of peanut plants exposed to Cd. Results showed that Cd exposure induced a reduction of peanut growth and produced changes in the histological structure with a deposit of unknown material on the epidermal and endodermal cells. When plants were exposed to 10 μM Cd, no modification of chlorophyll, lipid peroxides, carbonyl groups, or hydrogen peroxide (H₂O₂) content was observed. At this concentration, peanut leaves and roots glutathione (GSH) content decreased. However, peanut roots were able to synthesize different types of PCs (PC2, PC3, PC4). In conclusion, PC synthesis could prevent metal disturbance on cellular redox balance, avoiding oxidative damage to macromolecules.

  19. Effects of Cadmium pollution on oxidative stress and metallothionein content in Pirata subpiraticus(Araneae:Lycosidae)in different habitats%镉污染对不同生境拟水狼蛛氧化酶和金属硫蛋白应激的影响

    Institute of Scientific and Technical Information of China (English)

    张征田; 庞振凌; 夏敏; 梁子安; 杜瑞卿; 彭宇

    2011-01-01

    为探讨镉(Cd)对机体抗氧化功能及金属硫蛋白(MT)的影响,在室内分别用不添加Cd(2+)和添加浓度为20 mg/kgCd(2+)培养基培养的黑腹果蝇来饲喂4种不同生境下(S1,S2,S3和S4)拟水狼蛛,于饲喂5d、10d和20d后,分别测定其体内MT和丙二醛(MDA)的含量及超抗氧化酶(GST、SOD和CAT)活性.结果表明:(1)不同生境拟水狼蛛用不添加Cd(2+)培养基培养的黑腹果蝇饲喂后,不添加Cd(2+)对照组拟水狼蛛镉的积累量和MT含量无显著变化,但均显著低于添加Cd(2+)污染组.添加Cd(2+)污染组拟水狼蛛镉的积累量和MT含量都显著高于对照组,且均随着饲喂时间的延长而显著升高,具有明显的时间-效应关系(P<0.05).(2)在饲喂5d和10d后,不添加Cd饲喂的拟水狼蛛MDA含量和抗氧化酶系差异都不显著.添加Cd(2+)污染组(S1,S2和S3)MDA含量显著高于对照组(S4),MDA含量与饲喂时间呈显著正相关(P<0.05);GST、SOD和CAT等杭氧化酶活性污染组显著低于对照组,与饲喂时间呈显著负相关(P<0.05);饲喂20d后,污染组MDA含量和抗氧化酶(SOD和CAT)活性均与对照组无显著差异,但CST活性差异显著.%Heavy metals such as Cadmium (Cd) are one of the most fundamental causes of soil and water pollution in industrialized and developing countries. Cadmium (Cd) is a heavy metal that accumulates in the environment and causes pollution as well as intoxication of both vertebrates and invertebrates, although the mechanisms responsible for the toxicity of Cd are not well understood. Organisms inhabiting chronically polluted environments require additional expenditure of energy for supplementary detoxification. Superoxide dismutase, catalase and glutathione S-transferase (GST) , play key roles in protecting organisms from endogenous reactive oxygen species, whose activities are enhanced by environmental contaminants. The wolf spider Pirata subpiraticus (Araneae, Lycosidae) is a common, surface-active wolf spider

  20. Technetium incorporation into hematite (alpha-Fe2O3).

    Science.gov (United States)

    Skomurski, Frances N; Rosso, Kevin M; Krupka, Kenneth M; McGrail, B Pete

    2010-08-01

    Quantum-mechanical methods were used to evaluate mechanisms for possible structural incorporation of Tc species into the model iron oxide, hematite (alpha-Fe2O3). Using periodic supercell models, energies for charge-neutral incorporation of Tc4+ or TcO4- ions were calculated using either a Tc4+/Fe2+ substitution scheme on the metal sublattice, or by insertion of TcO4- as an interstitial species within a hypothetical vacancy cluster. Although pertechnetate incorporation is found to be invariably unfavorable, incorporation of small amounts of Tc4+ (at least 2.6 wt %) is energetically feasible. Energy minimized bond distances around this impurity are provided to aid in future spectroscopic identification of these impurity species. The calculations also show that Fe2+ and Tc4+ prefer to cluster in the hematite lattice, attributed to less net Coulombic repulsion relative to that of Fe3+-Fe3+. These modeling predictions are generally consistent with observed selective association of Tc with iron oxide under reducing conditions, and in residual waste solids from underground storage tanks at the U.S. Department of Energy Hanford Site (Washington, U.S.). Here, even though relatively high pH and oxidizing conditions are dominant, Tc incorporation into iron oxides and (oxy)hydroxides is prospectively enabled by prior reduction of TcO4- to Tc4+ via interaction with radiolytic species. PMID:20666557

  1. Incorporation, plurality, and the incorporation of plurals: a dynamic approach

    NARCIS (Netherlands)

    de Swart, H.E.; Farkas, D. F.

    2004-01-01

    This paper deals with the semantic properties of incorporated nominals that are present at clausal syntax. Such nominals exhibit a complex cluster of semantic properties, ranging from argument structure, scope, and number to discourse transparency. We develop an analysis of incorporation in the fram

  2. Assessment and management of risk to wildlife from cadmium

    International Nuclear Information System (INIS)

    Cadmium, a nonessential heavy metal that comes from natural and anthropogenic sources, is a teratogen, carcinogen, and a possible mutagen. Assessment of potential risk from cadmium requires understanding environmental exposure, mainly from ingestion, although there is some local exposure through inhalation. Chronic exposure is more problematic than acute exposure for wildlife. There is evidence for bioaccumulation, particularly in freshwater organisms, but evidence for biomagnification up the food chain is inconsistent; in some bird studies, cadmium levels were higher in species that are higher on the food chain than those that are lower. Some freshwater and marine invertebrates are more adversely affected by cadmium exposure than are birds and mammals. There is very little experimental laboratory research on the effects of cadmium in amphibians, birds and reptiles, and almost no data from studies of wildlife in nature. Managing the risk from cadmium to wildlife involves assessment (including ecological risk assessment), biomonitoring, setting benchmarks of effects, regulations and enforcement, and source reduction

  3. Study on electrokinetic remediation of cadmium contaminated soils

    Institute of Scientific and Technical Information of China (English)

    SHI Wen-xin; CUI Chong-wei; YU Shui-li; FENG Wei-ming

    2007-01-01

    Kaolinite from a lead-zinc mining district, which was spiked with cadmium, has been treated by electrokinetics to investigate effects of treatment time and applied voltage gradient. The results showed that the increased test duration had induced a higher removal rate of cadmium. Being treated for 7 days, cadmium was removed from kaolinite dramatically. It was also found that higher removal rate happened when a higher voltage gradient was applied and cadmium accumulated near the cathode because pH increased. Increase of pH near the cathode caused accumulation of cadmium. Moreover, it was observed that cation exchange membrane which was placed between kaolinite and cathode could make pH lower than the initial value and avoid the higher pH near the cathode. As a result, the high concentration accumulation of cadmium near the cathode was avoided.

  4. Research and Development of Cadmium Sulphoselenide Red Pigment

    Institute of Scientific and Technical Information of China (English)

    WU Jianfeng; LI Kun; XU Xiaohong; ZHANG Yaxiang; XU Xiaoyang; LAO Xinbin

    2015-01-01

    Cadmium sulphoselenide was synthesized continuous substitution solid solution and the only known pigment to yield bright red color on ceramic decoration. Encapsulated cadmium sulphoselenide pigments could yield abundant hues from yellow to red with high opacity at high temperature. The color generation has a linear function relation with the substitution rate. The encapsulation formation process of zirconium silicate encapsulated cadmium sulphoselenide was shown. Insufifcient encapsulation efifciency and potential hazard to human and environment had limited the industrial application of cadmium sulphoselenide red pigment. Ink-jet printing decoration required ifne size cadmium sulphoselenide red pigment on ceramic decoration. The review mainly focused on the synthesis techniques and industrial application of cadmium sulphoselenide red pigment.

  5. Ionic conductivity and interfacial properties of nanochitin-incorporated polyethylene oxide-LiN(C{sub 2}F{sub 5}SO{sub 2}){sub 2} polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Angulakshmi, N.; Prem Kumar, T. [Electrochemical Power Systems Division, Central Electrochemical Research Institute, Karaikudi 630006 (India); Thomas, Sabu [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560 (India); Manuel Stephan, A., E-mail: arulmanuel@gmail.co [Electrochemical Power Systems Division, Central Electrochemical Research Institute, Karaikudi 630006 (India)

    2010-01-25

    Nanocomposite polymer electrolytes (NCPE) composed of poly(ethylene oxide) and nanochitin for different concentrations of LiN(C{sub 2}F{sub 5}SO{sub 2}){sub 2} (LiBETI) were prepared by a completely dry, solvent-free procedure using a hot press. The thermal stability of NCPE membranes was investigated by DSC and TG-DTA. The membranes were subjected to SEM, ionic conductivity and FTIR analysis. Li/NCPE/Li symmetric cells were assembled and the variation of interfacial resistance as a function of time was also measured. The surface chemistry of lithium electrodes in contact with NCPE revealed the formation of Li-O-C and LiN compounds. LiFePO{sub 4}/NCPE/Li cell was assembled and the cycling profile showed a well-defined and reproducible shape of the voltage curves thus indicating a good cycling behavior of the cell at 60 deg. C.

  6. Distribution and oxidation state of Ge, Cu and Fe in sphalerite by μ-XRF and K-edge μ-XANES: insights into Ge incorporation, partitioning and isotopic fractionation

    Science.gov (United States)

    Belissont, Rémi; Muñoz, Manuel; Boiron, Marie-Christine; Luais, Béatrice; Mathon, Olivier

    2016-03-01

    Synchrotron-based microscale X-ray absorption near edge structure spectroscopy (μ-XANES) has been combined with X-ray fluorescence (μ-XRF) mapping to investigate Ge, Cu and Fe oxidation states in compositionally zoned Ge-rich sphalerite from the Saint-Salvy deposit (France). The present study aims at improving our understanding of substitution mechanisms and trace element uptake relative to Ge isotope fractionation in sphalerite. K-Edge XANES records of various Ge-, Cu- and Fe-bearing sulphides are presented for comparison with sphalerite, and ab initio calculations at the Ge K-edge complete our experimental data. The Ge K-edge spectra of the Ge-bearing sphalerite are identical to those of germanite, renierite and briartite, indicating the presence of tetrahedrally-coordinated Ge4+. In addition, Cu and Fe K-edge spectra suggest the presence of Cu+ and Fe2+, respectively, in the tetrahedral site. No significant differences in the oxidation states of Ge, Cu and Fe were observed within or between the zoning types or between the samples. The intake of Ge4+ in sphalerite may therefore occur in the tetrahedral divalent metal site via coupled substitutions charge-balanced by monovalent elements such as 3Zn2+ ↔ Ge4+ + 2Cu+, resulting in a strong Ge-Cu elemental correlation, or, when Ge does not correlate with monovalent elements, through the creation of lattice vacancies such as 2Zn2+ ↔ Ge4+ + □ (vacancy). The tetravalent state of Ge is compatible with temperature-related Ge isotopic fractionation and can explain the large range of δ74Ge measured in the Saint-Salvy sphalerite. Moreover, the exceptional enrichment in Ge and the large variations in the 'bulk' Ge contents in these sphalerites do not appear to be related to charge effects but would instead result from the effect of temperature-related partitioning.

  7. In search of biomonitors for cadmium: cadmium content of wild Swedish fauna during 1973-1976.

    Science.gov (United States)

    Frank, A

    1986-12-01

    Forty-five species of birds and 22 species of mammals of the terrestrial and aquatic fauna, herbivores as well as carnivores, were investigated during the period 1973-1976 for cadmium-accumulating properties in order to find biomonitors for cadmium in the Swedish environment. The herbivores of the terrestrial fauna, birds as well as mammals, are preferred to carnivores, since they demonstrate generally higher renal Cd levels. The moose (Alces alces), roe deer (Capreolus capreolus) and hare (Lepus europeus and Lepus timidus) were found to be suitable as biomonitors because of their common occurrence and uniform geographical distribution. The eider duck (Somateria mollissima), although a short-distance migrating bird whose diet is composed mainly of mussels and crustaceans, and which lives along a great part of the Swedish coastline, is suggested as a biomonitor of cadmium for the aquatic environment. The accumulation rate of cadmium in the kidneys is rapid. Renal levels of cadmium in the parts per million range are reached 10 weeks after hatching. Juvenile birds should be collected for monitoring purposes before leaving their feeding domains at the end of the summer. PMID:3810147

  8. Oral cadmium exposure of adults in Germany. 1: Cadmium content of foodstuffs and beverages.

    Science.gov (United States)

    Müller, M; Anke, M; Hartmann, E; Illing-Günther, H

    1996-04-01

    The cadmium contents of 94 and 105 foodstuffs bought in six-fold repetition in 1988 and in nine-fold repetition in 1991, respectively were analysed within the framework of a market-basket study. These foodstuffs were typical of German eating habits. Additionally, 170 samples of drinking water were investigated. The cadmium concentrations of the foodstuffs were comparable with results of recent studies carried out in Europe and North America. Fruit, milk and dairy products, sugar and sugar-rich foodstuffs as well as beverages showed mean cadmium contents cakes and pastries as well as farinaceous products were within the range of 20-40 ng/g. The most important bread, cakes and pastries (wheat and rye bread, toasted bread, rolls) contained 25-35 ng/g. A median cadmium concentration of 0.2 micrograms/l was found in the drinking water. As expected, liver and kidneys showed the highest cadmium levels of 73 and 204 ng/g, respectively on average. PMID:8718751

  9. N-acetyl-β-D-glucosaminidase activity in feral Carcinus maenas exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Sofia Raquel, E-mail: smesquita@ciimar.up.pt [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); ICBAS – Institute of Biomedical Sciences Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto (Portugal); Ergen, Şeyda Fikirdeşici [Faculty of Science, Ankara University, Department of Biology, 06100 Tandogan, Ankara (Turkey); Rodrigues, Aurélie Pinto [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); ICBAS – Institute of Biomedical Sciences Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto (Portugal); Oliva-Teles, M. Teresa; Delerue-Matos, Cristina [REQUIMTE, School of Engineering, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 431, 4200-072 Porto (Portugal); Guimarães, Laura, E-mail: lguimaraes@ciimar.up.pt [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal)

    2015-02-15

    Highlights: • Effects of Cd on NAGase activity of crabs from low impacted and polluted sites. • Inhibition of epidermal NAGase by Cd in crabs from both sites. • Inhibition of NAGase in digestive gland only in crabs from low impacted site. • Glutathione role in enhanced tolerance to Cd of crabs from polluted site. - Abstract: Cadmium is a priority hazardous substance, persistent in the aquatic environment, with the capacity to interfere with crustacean moulting. Moulting is a vital process dictating crustacean growth, reproduction and metamorphosis. However, for many organisms, moult disruption is difficult to evaluate in the short term, what limits its inclusion in monitoring programmes. N-acetyl-β-D-glucosaminidase (NAGase) is an enzyme acting in the final steps of the endocrine-regulated moulting cascade, allowing for the cast off of the old exoskeleton, with potential interest as a biomarker of moult disruption. This study investigated responses to waterborne cadmium of NAGase activity of Carcinus maenas originating from estuaries with different histories of anthropogenic contamination: a low impacted and a moderately polluted one. Crabs from both sites were individually exposed for seven days to cadmium concentrations ranging from 1.3 to 2000 μg/L. At the end of the assays, NAGase activity was assessed in the epidermis and digestive gland. Detoxification, antioxidant, energy production, and oxidative stress biomarkers implicated in cadmium metabolism and tolerance were also assessed to better understand differential NAGase responses: activity of glutathione S-transferases (GST), glutathione peroxidase (GPx) glutathione reductase (GR), levels of total glutathiones (TG), lipid peroxidation (LPO), lactate dehydrogenase (LDH), and NADP{sup +}-dependent isocitrate dehydrogenase (IDH). Animals from the moderately polluted estuary had lower NAGase activity both in the epidermis and digestive gland than in the low impacted site. NAGase activity in the

  10. N-acetyl-β-D-glucosaminidase activity in feral Carcinus maenas exposed to cadmium

    International Nuclear Information System (INIS)

    Highlights: • Effects of Cd on NAGase activity of crabs from low impacted and polluted sites. • Inhibition of epidermal NAGase by Cd in crabs from both sites. • Inhibition of NAGase in digestive gland only in crabs from low impacted site. • Glutathione role in enhanced tolerance to Cd of crabs from polluted site. - Abstract: Cadmium is a priority hazardous substance, persistent in the aquatic environment, with the capacity to interfere with crustacean moulting. Moulting is a vital process dictating crustacean growth, reproduction and metamorphosis. However, for many organisms, moult disruption is difficult to evaluate in the short term, what limits its inclusion in monitoring programmes. N-acetyl-β-D-glucosaminidase (NAGase) is an enzyme acting in the final steps of the endocrine-regulated moulting cascade, allowing for the cast off of the old exoskeleton, with potential interest as a biomarker of moult disruption. This study investigated responses to waterborne cadmium of NAGase activity of Carcinus maenas originating from estuaries with different histories of anthropogenic contamination: a low impacted and a moderately polluted one. Crabs from both sites were individually exposed for seven days to cadmium concentrations ranging from 1.3 to 2000 μg/L. At the end of the assays, NAGase activity was assessed in the epidermis and digestive gland. Detoxification, antioxidant, energy production, and oxidative stress biomarkers implicated in cadmium metabolism and tolerance were also assessed to better understand differential NAGase responses: activity of glutathione S-transferases (GST), glutathione peroxidase (GPx) glutathione reductase (GR), levels of total glutathiones (TG), lipid peroxidation (LPO), lactate dehydrogenase (LDH), and NADP+-dependent isocitrate dehydrogenase (IDH). Animals from the moderately polluted estuary had lower NAGase activity both in the epidermis and digestive gland than in the low impacted site. NAGase activity in the epidermis and

  11. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method

    OpenAIRE

    Jinzhan Su; Tao Zhang; Yufeng Li; Yubin Chen; Maochang Liu

    2016-01-01

    Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS) photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM), X-ray fluorescence-spectrometry (XRF), UV-Vis absorption spect...

  12. Effect of Tributyltin, Cadmium, and Their Combination on Physiological Responses in Juvenile Grass Carp.

    Science.gov (United States)

    Mu, Wei-Na; Li, Zhi-Hua; Zhong, Li-Qiao; Wu, Yan-Hua

    2016-09-01

    Tributyltin (TBT) and cadmium (Cd) are two common pollutants in aquatic environments. This study was designed to examine the physiological responses of juvenile Grass Carp Ctenopharyngodon idella to TBT, Cd, and their combination. Fish were apportioned into a control group, a TBT group (7.5 μg/L), a Cd group (2.97 mg/L), and a TBT-Cd group (7.5 μg/L TBT, 2.97 mg/L Cd(2+)) for 7 d. The following activities were measured: Na(+),K(+)-ATPase in gill tissues; nitric oxide synthase (NOS), acetylcholinesterase (AChE), and monoamine oxidase (MAO) in brain tissues; and lipid peroxidation (LPO), malondialdehyde (MDA), total antioxidative capacity (T-AOC), and glutathione (GSH) in liver tissues. Cadmium-induced stress was suggested by alterations in antioxidant responses (MDA, LPO, and T-AOC) and neurological parameters (AChE, MAO, and NOS). Cadmium also induced Na(+),K(+)-ATPase and GSH activity. Compared with the responses among the Cd group, the combination of TBT and Cd not only decreased the level of GSH and Na(+),K(+)-ATPase but also increased the levels of MDA, LPO, AChE, MAO, and NOS. These results suggest that a combination of TBT and Cd could reduce the adverse effects of Cd on Grass Carp. However, the exact mechanisms for the combined effects TBT and Cd on these biomarkers require further investigation. Received September 28, 2015; accepted April 17, 2016. PMID:27484920

  13. The potential protective role of Physalis peruviana L. fruit in cadmium-induced hepatotoxicity and nephrotoxicity.

    Science.gov (United States)

    Dkhil, Mohamed A; Al-Quraishy, Saleh; Diab, Marwa M S; Othman, Mohamed S; Aref, Ahmed M; Abdel Moneim, Ahmed E

    2014-12-01

    This study aimed to investigate the potential protective role of Physalis peruviana L. (family Solanaceae) against cadmium-induced hepatorenal toxicity in Wistar rats. Herein, cadmium chloride (CdCl2) (6.5 mg/kg bwt/day) was intraperitoneally injected for 5 days, and methanolic extract of physalis (MEPh) was pre-administered to a group of Cd-treated rats by an oral administration at a daily dose of 200 mg/kg bwt for 5 days. The findings revealed that CdCl2 injection induced significant decreases in kidney weight and kidney index. Cadmium intoxication increased the activities of liver enzymes and the bilirubin level, in addition to the levels of uric acid, urea and creatinine were increased in the serum. The pre-administration of MEPh alleviated hepatorenal toxicity in Cd-treated rats. Physalis was noted to play a good hepatorenal protective role, reducing lipid peroxidation, nitric oxide, and enhancing enzymatic activities and non-enzymatic antioxidant molecule, glutathione, in hepatic and renal tissues of Cd-treated rats. Moreover, physalis treatment was able to reverse the histopathological changes in liver and kidney tissues and also increased the expression of Bcl-2 protein in liver and kidney of rats. Overall, the results showed that MEPh can induce antioxidant and anti-apoptotic effects and also exerts beneficial effects for the treatment of Cd-induced hepatorenal toxicity. PMID:25265456

  14. Amelioration of cadmium-induced changes in biochemical parameters of the muscle of Common Carp (Cyprinus carpio by Vitamin C and Chitosan

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2015-12-01

    Full Text Available The aim of this study was to investigate the effects of administering antioxidants, including vitamin C and chitosan on oxidative stress markers in muscle as edible tissues of Cyprinus carpio exposed to cadmium chloride. In this experiment, by exposing to 0.2 mg/L cadmium chloride for 21 days, fish were fed a normal diet, diet containing chitosan (1000 mg/kg diet, vitamin C (1000 mg/kg diet or both vitamin C and chitosan. Oxidative stress markers, including the activity of catalase, total antioxidant and malondialdehyde (MDA as well as biochemical parameters, including the activity of aspartate aminotransferase (AST, alanine aminotransferase (ALT, creatine phosphokinase (CPK, lactate dehydrogenase (LDH, and acetylcholinesterase (AChE were measured. Fish exposure to cadmium chloride significantly increased AST, LDH, CPK, catalase, and MDA activity, while it significantly decreased AST and AChE activity, and levels of total antioxidant in muscle cells. Administration of chitosan or vitamin C alone or in combination with each other to fish exposed to cadmium chloride was effective in regulating ALT, CPK, and catalase activity. Although administration of vitamin C and chitosan caused a significant decrease in MDA, AST and LDH, these enzymes were still significantly higher than those in the control group. Administration of vitamin C and chitosan had no significant effects on the activity of AChE and levels of total antioxidant. Although, chitosan alone could not prevent oxidative stress damages in muscle tissues of cadmium-treated fish, administration of vitamin C combined with chitosan may increase the efficiency of antioxidant defense system and improve the detoxification system in the muscles of fish exposed to cadmium chloride.

  15. Extraction-photometric determination of cadmium in meat products

    Energy Technology Data Exchange (ETDEWEB)

    Krylova, A.N.; Malyarova, M.A.; Zhulenko, V.N.

    1986-06-01

    As a result of industrial discharges, burning of solid and liquid fuels, and recycling of metal scrap, cadmium compounds enter the atmosphere and drop into the water and soil causing contamination. In this paper, a method was developed for determining cadmium in meat products. It involves wet ashing the sample, extractive separation of the cadmium as the diethyldithiocarbamate, reextraction, and determination as cadmium dithizonate or as a complex with 2,2'-dipyridyl. The detection limit with dithizone is 0.005 mg/kg and with 2,2'-dipyridyl 0.05 mg/kg. An analysis is shown to take less than 60 minutes.

  16. Cadmium elemination from phosphoric acid by ionic flotation

    International Nuclear Information System (INIS)

    The ion flotation process for the recovery of cadmium from wet phosphoric acid (30%P2O5) has been studied. This technique combines a chemical recation between the collector and the cadmium to form a precipitate (sublate) which is carried to the surface of the solution by air bubbles. the resulting foam containing the cadmium may then separated from solution. The influence of parameters such as collector and cadmium concentration as well as iron content have been investigated for the case a synthetic acid (30% P2O5). The result have been applied to the industrial phosphoric acid produced from Djebel Onk's phosphates (Algeria)

  17. Bioremoval of cadmium by lemna minor in different aquatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Uysal, Yagmur [Dept. of Environmental Engineering, Kahramanmaras Sutcu Imam University, Kahramanmaras (Turkey); Taner, Fadime [Dept. of Environmental Engineering, Mersin University, Mersin (Turkey)

    2010-04-15

    This study was undertaken to determine the cadmium removal efficiency of Lemna minor when it was used for treatment of wastewater having different characteristics, i. e., pH, temperature and cadmium concentration. Plants were cultivated in different pH solutions (4.5-8.0) and temperatures (15-35 C) in the presence of cadmium (0.1-10.0 mg/L) for 168 h. The amount of biomass obtained in the study period, the concentrations of cadmium in the tissues and in the media and net uptake of cadmium by Lemna have been determined for each condition. The percentages of cadmium uptake (PMU) and bioconcentration factors (BCF) were also calculated. The highest accumulation was obtained for the highest cadmium concentration of 10.0 mg Cd/L as 11.668 mg Cd/g at pH 6.0, and as 38.650 mg Cd/g at 35 C and pH 5.0. The cadmium accumulation gradually increased with initial concentration of the medium, but the opposite trend was observed for the PMU. However, the maximum PMU was obtained as 52.2% in the solution with the lowest concentration of 0.1 mg Cd/L. A mathematical model was used to describe the cadmium uptake and the equation obtained was seen to fit the experimental data very well. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. Effects of Cadmium on BMP Induced Bone Formation

    Institute of Scientific and Technical Information of China (English)

    陈秋生; 徐顺清

    2003-01-01

    To demonstrate the direct effects of cadmium on activities of bone morphogenetic protein (BMP), a complex containing BMP and cadmium chloride (CdCl2) was implanted beneath the abdominal skin of young male Wistar rats. The activity of BMP was studied by observing the histological changes, and measuring the activity of alkaline phosphatase (ALP) and acid phosphatase (ACP) and calcium content of the implants at different time points. Our results showed that during bone formation induced by BMP, cadmium inhibited the activities of osteoblasts and osteoclasts, and slowed the deposition of calcium. It is concluded that cadmium can directly affect biological activities of BMP directly.

  19. β—Correction Spectrophotometric Determination of Cadmium with Cadion

    Institute of Scientific and Technical Information of China (English)

    郜洪文

    1995-01-01

    Cadmium has been determined by β-correction spectrophotometry with cadion,p-nitrobenzenediazoaminoaz-obenzone,and a non-ionic surfactant,tuiton X-100.The real absorbance of a Cd-cadion chelate in the colored solution can be accurately determined and the complex-ratio of cadion with Cd(II) has been worked out to be 2.Beer's law is obeyed over the concentration range of 0-0.20mg/1 cadmium and the detec-tion limit for cadmium is only 0.003mg/1.Satisfactory experimental results are presented with respect to the determination of trace cadmium in wastewaters.

  20. Elektrokemisk fjernelse af cadmium fra bioasker

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter;

    Hosliggende rapport formidler resultaterne fra PSO-projektet: ”Elektrokemisk fjernelse af cadmium fra bioasker” (PSO-F&U 3206), finansieret af Elkraft System og Energi E2 A/S. Projektet blev gennemført i perioden 01.05.2003 – 30.06.2004, og partnerne var Energi E2 A/S, BYG-DTU og Krüger A/S, med...... BYG-DTU som den primært udførende part. Projektets formål var at undersøge, om den elektrodialytiske rensningsmetode kunne bruges til at reducere indholdet af cadmium i asker fra biobrændsel (f.eks. træflis og halm) med henblik på nyttiggørelse af askerne. Projektet havde nær sammenhæng med det...

  1. Electron mobility in mercury cadmium telluride

    Science.gov (United States)

    Patterson, James D.

    1988-01-01

    A previously developed program, which includes all electronic interactions thought to be important, does not correctly predict the value of electron mobility in mercury cadmium telluride particularly near room temperature. Part of the reason for this discrepancy is thought to be the way screening is handled. It seems likely that there are a number of contributors to errors in the calculation. The objective is to survey the calculation, locate reasons for differences between experiment and calculation, and suggest improvements.

  2. ELECTROKINETIC REMEDIATION STUDY FOR CADMIUM CONTAMINATED SOIL

    OpenAIRE

    P. Bala Ramudu; R. P. Tiwari; Srivastava, R. K.

    2007-01-01

    This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself wa...

  3. Determination of cadmium and lead species and phytochelatins in pea (Pisum sativum) by HPLC-ICP-MS and HPLC-ESI-MSn.

    Science.gov (United States)

    Barałkiewicz, Danuta; Kózka, Małgorzata; Piechalak, Aneta; Tomaszewska, Barbara; Sobczak, Paweł

    2009-07-15

    An analytical approach based on hyphenated techniques was used for studying the speciation of cadmium and lead in Pisum sativum. Proper preservation conditions were employed to avoid the oxidation of -SH groups and corresponding decomposition of metal-binding complexes. SEC column was washed with 5 mM beta-mercaptoethanol and then samples were analysed using ICP-MS as a detector. Results showed that cadmium is the inhibitor of lead uptake. HPLC-ESI-MS(n) assays revealed fragmentation pathways of phytochelatins.

  4. Gene expression profiling in rat kidney after intratracheal exposure to cadmium-doped nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Coccini, Teresa, E-mail: teresa.coccini@fsm.it; Roda, Elisa [University of Pavia, European Centre for Nanomedicine (Italy); Fabbri, Marco; Sacco, Maria Grazia; Gribaldo, Laura [European Commission Institute for Health and Consumer Protection (IHCP), JRC (Italy); Manzo, Luigi [University of Pavia, Europe