The method of isotope dilution thermal ionization mass spectrometry able to trace to SI was developed to accurately measure trace amount of cadmium in the rice powder sample from CCQM-K24 international key comparison organized by CCQM(Comité Consultatif pour la Quantité de Matière, Paris). By comparison with our previous work, there was much improvement in aspects of digestion of the rice powder sample, separation of cadmium from the sample and dry-mass correction. As a result, the blank of this procedure was reduced and the measurement precisions of isotopic ratios of cadmium were increased. In addition, the uncertainty evaluation of the entire process of measurement was profoundly studied. The analytical result of this work (14.53±0.15) nmol/g was in agreement with the certified value.
Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine copper, arsenic, cadmium, lead in athletic food using Sc, Ge, In, Bi as an internal standard. The linear correlation factor for four elements are higher than 0.999. Recoveries of spiked samples are in the range of 85.5%-115.5% and precision was fine, RSD is lower than 5.0%. And these are close agreement with the reference values in three standard reference materials of GBW08503, NBS1568, GBW08571. It indicates that the method is simple, rapid, sensitive and accurate, which can meet the demand for copper, arsenic, cadmium, lead analysis in athletic food.
The objective of this experiment was to study the effects of malic, tartaric, oxalic, and citric acid on the adsorption and desorption characteristics of Cd by two typical anthropic soils （lou soil and irrigation-silted soil） in North-west China. Cadmium adsorption and desorption were studied under a range of temperatures （25℃, 30℃, 35℃, 40℃）, organic acid concentrations （0.5-5.0 mmol·L-1）, and pH values （2-8）. The results showed that the Cd adsorption capacity of the lou soil was significantly greater than that of the irrigation-silted soil. Generally, Cd adsorption increased as the temperature increased. In the presence of NaNO3, the adsorption of Cd was endothermic with △H values of 31.365 kJ·mo1-1 for lou soil and 28.278 kJ·mol-1 for irrigation-silted soil. The endothermic reaction indicated that H bonds were the main driving force for Cd adsorption in both soils. However, different concentrations of organic acids showed various influences on the two soils. In the presence of citric acid, chemical adsorption and van der Waals interactions were the main driving forces for Cd adsorption rather than H bonds. Although the types of organic acids and soil properties were different, the effects of the organic acids on the adsorption and desorption of Cd were similar in the two soils. The adsorption percentage of Cd generally decreased as organic acid concentrations increased. In contrast, the adsorption percentage increased as the pH of the initial solution increased. The exception was that adsorption percentage of Cd increased slightly as oxalic acid concentrations increased. In contrast, the desorption percentage of Cd increased with increasing concentrations of organic acids but decreased as the initial solution pH increased.
To help reduce risks of heavy metal pollution, two pot experiments were conducted to investigate the variations, transfer potential, and stability of Cadmium （Cd） and Lead （Pb） accumulations in celery （Apium graveolens L.） and to screen for low Cd and Pb accumulative cultivars. The maximum differences in shoot Cd concentration were 4.7-fold under low-Cd exposure and 3.3-fold under high-Cd exposure. These genotype variations in Cd accumulation are sufficiently large to help reduce Cd contamination risk in soil by using the Low-Cd-Accumulative genotypes. Cd accumulation of the Low-Cd-Accumulative genotypes is significantly positive correlated with Pb accumulation. Evidence obtained proves that Cd and Pb accumulations in celery are stable and genotype-dependent at the cultivar level. The presence of high-Pb contamination in soil promoted Cd accumulation in shoots of celery. Celery is considered a species with high risks in Cd pollution and low risks in Pb pollution. Among the tested cultivars, cv. Shuanggang- kangbing （SGKB） had the lowest shoot Cd and Pb accumulating abilities, and thus is the most important material for breeding of pollution-safe cultivars （PSCs） to minimize Cd and Pb accumulations in celery.
Cadmium chalcogenide nanowires have demonstrated superior electrical and optical properties,and have emerged as prominent building blocks for nanoscale electronic and optoelectronic devices.In addition to the effort devoted to advance techniques of fabricating high quality nanowires,much has been endeavored to elucidate their unique physical properties for better design and development of functional devices with low power consumption and high performance.Herein,this article provides a comprehensive review of the forefront research on cadmium chalcogenide nanowires,ranging from material synthesis,property characterizations,and device applications.
<正>Reproduced by Zhao Wenjing from China Rare Earth Information Center,according to presentation of Cao Guoqing,from State Quafity Supervision and Inspection Center of Chemical Power Products,at 2015 China Rare Earth Hydrogen Storage Forum Battery is the key to develop energy technology for it can improve energy yield and energy use efficiency.
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.
In this study,HPLC-MS and ICP-MS methods wereused for the determination of histidine and cadmiumin Eleagnusangustifolia L.,Vitisvinifera L.and Nerium oleander L.leaves taken from industrial area including Gaziantep and Bursa cities.To histidine determination by HPLC-MS,flow rate of mobile phase,fragmentor potential,injection volume and column temperature were optimized as 0.2mL·min-1,70V,15μL and 20℃,respectively.For extraction of histidine from plants,distilled water was used by applying on 90℃and 30min.The concentrations(as mg·kg-1)of histidine were found to be in range of 822for Eleagnusangustifolia L.,1033for Vitisvinifera L.and 611for Nerium oleander L.The concentrations of cadmium were found to be in ranges of 621μg·kg-1 for Vitisvinifera L.15110μg·kg-1 for Eleagnusangustifolia L.and 63218μg·kg-1 for Nerium oleander L.
Glucose （Glu） is involved in not only plant physiological and developmental events but also plant responses to abiotic stresses. Here, we found that the exogenous Glu improved root and shoot growth, reduced shoot cadmium （Cd） concentration, and rescued Cd-induced chlorosis in Arabidopsis thaliana （Columbia ecotype, Col-0） under Cd stressed conditions. Glucose increased Cd retained in the roots, thus reducing its translocation from root to shoot significantly. The most Cd retained in the roots was found in the hemicellulose 1. Glucose combined with Cd （Glu t Cd） treatment did not affect the content of pectin and its binding capacity of Cd while it increased the content of hemicelluloses 1 and the amount of Cd retained in it significantly. Furthermore, Leadmium Green staining indicated that more Cd was compartmented into vacuoles in Glu t Cd treatment compared with Cd treatment alone, which was in accordance with the＆amp;nbsp;significant upregulation of the expression of tonoplast-localized metal transporter genes, suggesting that com-partmentation of Cd into vacuoles also contributes to the Glu-alleviated Cd toxicity. Taken together, we demonstrated that Glu-alleviated Cd toxicity is mediated through increas-ing Cd fixation in the root cell wall and sequestration into the vacuoles.
Cadmium （Cd） is one of the most toxic elements and can be accumulated in plants easily;meanwhile, eIF5A is a highly conserved protein in all eukaryotic organisms. The present work tried to investigate whether eIF5A is involved in Cd accumulation and sensitivity in Arabidopsis （Arabidopsis thaliana L.） by comparing the wild-type Columbia-0 （Col-0） with a knockdown mutant of AteIF5A-2, fbr12-3 under Cd stress conditions. The results showed that the mutant fbr12-3 accumulated more Cd in roots and shoots and had significantly lower chlorophyll content, shorter root length, and smaller biomass, suggesting that downregulation of AteIF5A-2 makes the mutant more Cd sensitive. Real-time polymerase chain reaction revealed that the expressions of metal transporters involved in Cd uptake and translocation including IRT1, ZIP1, AtNramp3, and AtHMA4 were signifi-cantly increased but the expressions of PCS1 and PCS2 related to Cd detoxification were decreased notably in＆amp;nbsp;fbr12-3 compared with Col-0. As a result, an increase in MDA and H2O2 content but decrease in root trolox, glutathione and proline content under Cd stress was observed, indicating that a severer oxidative stress occurs in the mutant. All these results demonstrated for the first time that AteIF5A influences Cd sensitivity by affecting Cd uptake, accumulation, and detoxification in Arabidopsis.