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Impact of S fertilization on Cu mobility and transformation in contaminated paddy soils has been little reported. In this study, we investigated the dynamics and transformation of dissolved and colloidal Cu in the pore water of a contaminated paddy soil after applying ammonium sulphate (AS) and sulfur coated urea (SCU) with various flooding periods (1, 7 and 60 days). Compared to the control soil, the AS-treated soil released more colloidal and dissolved Cu over the entire flooding period, while the SCU-treated soil had lower colloidal Cu after 7-day flooding but higher colloidal and dissolved Cu after 60-day flooding. Microscopic X-ray fluorescence (μ-XRF) analysis found a close relationship between Fe and Cu distribution on soil colloids after 60-day flooding, implying the formation of colloidal Fe/Cu sulphide coprecipitates. Cu K-edge X-ray absorption near-edge structure (XANES) spectroscopy directly revealed the transformation of outer-sphere complexed Cu(II) species to Cu(II) sulphide and reduced Cu 2 O in the colloids of S-treated soils after 60-day flooding. These results demonstrated the great influence of S fertilization on pore-water Cu mobility by forming Cu sulphide under flooding conditions, which facilitated our understanding and control of Cu loss in contaminated paddy soils under S fertilization. [ABSTRACT FROM AUTHOR]

Background and aims: Metal species in rhizosphere soil profoundly influence their mobility and phytoavailability. Clarifying the speciation transformation of heavy metals helps understand their translocation and accumulation in plants. Methods: Single extraction, selective sequential extraction (SSE) and X-ray absorption near-edge structure (XANES) spectroscopy were employed to investigate the speciation transformation of lead (Pb) and its influence on metal accumulation in tea plants after the addition of tea polyphenols (TPs). Results: Pb content was decreased in young leaves and stems, whereas increased in roots, after TPs were amended to soil. Both SSE and XANES analysis suggested bioavailable Pb was transformed to organically bound Pb after the addition of TPs. The increased percentage of organically bound Pb might be fixed in the cell wall of plant root through a ternary complex formed between the Pb-organic matter complex and cell wall components. Therefore, Pb translocation from roots to young tissues was decreased. Conclusions: Pb phytoavailability change was driven by its speciation transformation after the addition of TPs. Combined SSE and XANES spectroscopy represent powerful tools to study metal speciation transformation in plant and soil systems. [ABSTRACT FROM AUTHOR]

Heavy metal pollution in the soil of farmland is regarded as serious threats to agricultural production environment in China. Zihu River is located in Nanjing, Jiangsu, China. The source of Zihu River is the purple mountain, a famous local mountain. The pollution problem of Zihu River has aroused public concerns because of heavy metal contamination caused by sewage. To investigate and assess the situation of heavy metal pollution of Zihu River region, concentrations of heavy metals including As, Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined and analyzed for brook water, the soil from river silt and riverbank, as well as for the riverbank plants of nine species. These species include Trifolium repens, Alternanthera philoxeroides, Chenopodium glaucum, Commelina communis, Ranunculus ternatus, Poa annua, Ligustrum lucidum, Lycium chinense, Broussonetia papyrifera. An assessment of heavy-metal contamination was conducted by means of pollution index (Pi). Such data may provide information for screening of heavy metal accumulator, and for phytoremediation of heavy metals. The results indicated that serious contamination of Cd and Mn was found in the brook water, the concentrations for Cd and Mn were 0.003 mg/L and 0.124 mg/L, respectively. Among the heavy metals in the soil from the river silt, contamination of Zn, Cd and Cu was serious based on the Pi values (18.89, 8.53 and 6.25, respectively), with the order of potential ecological risk as: Zn>Cd>Cu>Pb>As>Ni> Cr>Mn. Pearson correlation analysis showed a significantly (p < 0.05) positive correlation among concentrations of heavy metals in the riparian soil, which indicated that they were mainly polluted by sewage and silt. High concentrations of Cd, Zn and Cu were investigated from the soil of the riverbank based on the Pi values (3.68, 3.61 and 3.41, respectively). The bioconcentration factor (BFs) to Cd, Cr and Pb were quite lower among all the nine species due probably to the selective absorption of the plants. Because Pb is toxic to all plants, the transfer factors (TF) to Pb for all the nine species were typically less than 1. This meant that they were all compartment types to Pb. Plants growing on the sites with heavy metal pollution can gradually evolve into differentiated ecotypes based on the survey of plant population and the result of heavy metal concentration. Wetland ecotypes, Alternanthera philoxeroides and Ranunculus ternatus, have an advantage for accumulating of heavy metals. Poa annua, Chenopodium glaucum and Lycium chinense can resistant to absorption heavy metals. Broussonetia papyrifera, a species of woody plants, will play a great function in the field of phytoremediation for soils contaminated by heavy metals in the future due to its higher bioconcentration factor and transfer factor to some heavy metals, as well as its huge biomass. This case study also provided useful information for monitoring of heavy metals and phytoremediation of river systems contaminated among other cities. [ABSTRACT FROM AUTHOR]

The inhibitory effect of barley straw ( Hordeum vulgare) on cyanobacteria has been observed in many field and laboratory studies for over 30 years, although the compounds responsible for this anti-cyanobacterial effect have remained unknown. In this study, a pair of chiral flavonolignans were isolated from barley straw extract using a bioassay-guided isolation procedure against Microcystis sp. The structures of the allelopathic compounds were elucidated by NMR (nuclear magnetic resonance) and HPLC-MS (high performance liquid chromatography-mass spectrometry), and turned out to be salcolin A and B. The enantiomers differ in their anti-cyanobacterial abilities. Both enantiomers exhibited inhibitory effects on Microcystis sp., and the EC50 (concentration for 50% of maximal effect) of salcolin A and B were 6.02 × 10−5 and 9.60 × 10−5 mol l−1, respectively. Furthermore, the modes of actions of the enantiomers were investigated and compared at a single cell level by flow cytometry. Salcolin A was found to induce an increase on cyanobacterial intracellular ROS (reactive oxygen species) levels and to inhibit esterase activity, whereas salcolin B caused leakages of cyanobacterial cytoplasms. Thus, salcolin A was more 'algistatic', and salcolin B was more 'algicidal'. This study suggests that salcolin is the key allelochemical in barley straw's inhibitory effect on cyanobacteria and could be used as an agent in the future control of cyanobacterial harmful algae blooms. [ABSTRACT FROM AUTHOR]

Support vector machine (SVM) classification models were constructed using a radial basis functions (RBF). These models were used for classification according to dissolved oxygen, permanganate index, ammoniac nitrogen, total nitrogen, or total phosphorus. Cross-validation and grid-search were applied to find satisfactory parameters for RBF for the improved models. Then the improved models were used to assess water quality utilizing a real-world data set (surface water quality monitoring data). The data set was comprised of more than 2,000 water samples representing 172 different sites monitored for one hydrological year. The results showed that the method presented in this paper had excellent performance, and the SVM classification models performed relatively better than the Linear Discriminant Analysis and Quadratic Discriminant Analysis models for classification. [ABSTRACT FROM AUTHOR]

The article presents several abstracts which were presented at the International Pediatric Association Congress, which was held in Shanghai, China on August 30-September 3, 2013, including abstracts on renal scarring in children with first pyelonephritis, urinary tract infections in children and urinary tract infection in infants with antenatally detected duplex kidneys.

In the present study, pottery glaze was investigated as an excellent adsorbent for the removal of Cu(II) ions from aqueous solution. Effect of concentration, contact time, pH, and effect of electrolyte concentration, adsorbent doses and temperature were studied by using batch process to optimize conditions for maximum adsorption. Equilibrium isotherm data were analyzed using Langmuir, Freundlich and Temkin isotherms at 30, 40 and 50°C. Thermodynamic parameters such as standard enthalpy change (ΔH), free energy change (ΔG) and entropy change (ΔS) were also evaluated. These parameters indicated that adsorption process is endothermic and spontaneous in nature. The mean energy calculated from Dubinin-Radushkeuich (D-R) isotherms showed chemical nature of adsorption. The kinetic data were evaluated using the pseudo-first-order and pseudo-second order kinetic equations and it was found that data best fitted pseudo-second-order model over a wide range of initial Cu(II) concentrations supporting that chemisorption process was involved. The adsorption and desorption studies carried out by batch process suggested 100% desorption of Cu(II) ions with 0.1 N HCl solution. [ABSTRACT FROM AUTHOR]

To assess the effects of single and combined pollution of cadmium (Cd) and mercury (Hg) on soil microbial community structural and functional diversities, an incubation experiment was conducted, by employing two soils, namely, the marine sediment silty loam soil and the yellowish-red soil, in which five levels of Cd, Hg and Cd and Hg in combination were added. After being incubated for 56 days, the phospholipid fatty acids (PLFAs) profile and sole carbon source utilization pattern (BIOLOG) of the samples were tested. The results showed that the composition of the microbial communities changed significantly at different levels of metals application. The principal component analyses (PCA) of PLFAs indicated that the structure of the microbial community was also significantly altered with increasing levels of metals, with increasing PLFAs biomarkers for fungi and actinomycetes, and increasing ratio of Gram-positive to Gram-negative bacteria. Sole carbon source utilization pattern analysis revealed that single and combined application of Cd and Hg inhibited significantly the functional activity of soil microorganisms, the functional diversity indices [Richness ( S), Shannon-Wiener indices ( H) and Evenness ( E)] were significantly lower in polluted soils than those in non-polluted soils, which also significantly altered with increasing levels of metals. PCA for the sole carbon source utilization pattern also indicated that the metal contamination could result in a variable soil microbial community. The results revealed that the combination of Cd and Hg had higher toxicity to soil microbial community structural and functional diversities than the individual application of Cd or Hg. [ABSTRACT FROM AUTHOR]

Abstract: Phytolacca americana L. (pokeweed) is a promising species for Cd phytoextraction with large biomass and fast growth rate. To further understand the mechanisms involved in Cd tolerance and detoxification, the present study investigated subcellular distribution and chemical forms of Cd in pokeweed. Subcellular fractionation of Cd-containing tissues indicated that both in root and leaves, the majority of the element was located in soluble fraction and cell walls. Meanwhile, Cd taken up by pokeweed existed in different chemical forms. Results showed that the greatest amount of Cd was found in the extraction of 80% ethanol in roots, followed by 1M NaCl, d-H2O and 2% HAc, while in leaves and stems, most of the Cd was extracted by 1M NaCl, and the subdominant amount of Cd was extracted by 80% ethanol. It could be suggested that Cd compartmentation with organo-ligands in vacuole or integrated with pectates and proteins in cell wall might be responsible for the adaptation of pokeweed to Cd stress. [Copyright &y& Elsevier]

Lead (Pb) and arsenic (As) exist in soil with different ionic forms, and it is difficult to immobilize simultaneously Pb and As in soil. The objective of this study is to determine the effects of water management including flooding (FL), alternate wetting and drying (AWD) and dry farming (DF) combined with addition of phosphate (P) on the accumulation of Pb and As in rice. Our results showed that Pb accumulated in root during vegetative stage, and most of As in root was transported to the above ground parts during the reproductive stage. Pb was evenly distributed in grains, and As was mostly accumulated in bran and aleurone layer. Water management had a reverse effect on the accumulation of Pb and As in rice. However, the effects of P on arid soil environment and Pb, As accumulation in rice were stronger than that in flooded soil. Application of P under AWD treatment could maintain a similar quantity of Fe plaque with flooding, decrease the availability of Pb in rhizosphere soil, reduce Pb and As accumulation in root, and result in the reduction of Pb and As accumulation in grains by 86% and 66% respectively. Besides, our study also found that flooding or AWD during vegetative stage facilitated the formation of iron plaque. In conclusion, AWD combined with P application could maintain a relatively lower concentrations of Pb and As in grains. [Display omitted] • Lead accumulated in root primarily during the vegetative stage. • Arsenic in root was transported to aboveground parts during the reproductive stage. • Flooding or AWD during the vegetative stage in soil would help to form iron plaque. • AWD combined with application of P could decrease simultaneously lead and arsenic in grains. • Lead was distributed evenly in grains, and arsenic was mostly accumulated in bran and aleurone layer. [ABSTRACT FROM AUTHOR]

Recent years have seen the development of various power electronic conditioners with rapid advancements in their topological layouts and control algorithms. The examples are active power filters (APFs), fault current limiters (FCLs) and uninterruptible power supplies (UPSs). There is, however, a lack of international research attention on the integration of the various merits of the different classes of power conditioners to form a universal system that provides appropriate power compensation to utility systems under various disturbance conditions. The paper therefore attempts to integrate the harmonic current compensation of an APF when supplying non-linear loads, the fault current limiting and the bus voltage enhancement capabilities of a FCL, and the voltage regulation and backup power supply features of a UPS to form a universal power conditioner which significantly enhances the quality of power supplied under various system conditions. [ABSTRACT FROM AUTHOR]

The aggregation of nanoscale zero-valent iron (nZVI) particles and their limited transport ability in environmental media hinder their application in environmental remediation. In this study, the Cr(VI) removal efficiency, transport performance, and toxicity of nZVI and bentonite-modified nZVI (B-nZVI) were investigated. Compared with nZVI, B-nZVI improved the removal efficiency of Cr(VI) by 10%, and also significantly increased the transport in quartz sand and soil. Increasing the flow rate can enhance the transport of nZVI and B-nZVI in the quartz sand columns. The transport of the two materials in different soils was negatively correlated with the clay composition. Besides, modification of nZVI by bentonite could reduce toxicity to luminous bacteria (Photobacterium phosphereum T3) and ryegrass (Lolium perenne L.). Compared with Fe-EDTA, the transfer factors of nZVI and B-nZVI were 65.0% and 66.4% lower, respectively. This indicated that although iron nanoparticles accumulated in the roots of ryegrass, they were difficult to be transported to the shoots. The results of this study indicate that B-nZVI has a strong application potential in in situ environmental remediation. [ABSTRACT FROM AUTHOR]

• Cr(VI) reduction by P. oxalicum SL2 in medium was accelerated by Ca2+ and SO 4 2−. • High Ca2+ concentration resulted in the production of calcium oxalate crystals. • P. oxalicum SL2 could reduce the toxicity of Cr(VI) by synthesizing thiol compounds (Cys and GSH). Some ions in soils may affect the growth and metabolism of microorganisms and subsequently alter the remediation efficiency of Cr(VI). Here, the effects of different Ca2+ and SO 4 2− levels on the reduction of Cr(VI) by Penicillium oxalicum SL2 were investigated. The results showed that Cr(VI) reduction by P. oxalicum SL2 in potato dextrose liquid (PDL) medium was accelerated by the presence of exogenous Ca2+ and SO 4 2−. The Cr(VI) reduction rates were increased by 52.5% (200 mg L−1 Ca2+ treated) and 55.9% (2000 mg L−1 SO 4 2− treated), respectively. High concentration of Ca2+ in medium resulted in the production of calcium oxalate crystals, which was contributed to the adsorption of chromium. In addition, X-ray absorption near-edge spectroscopy (XANES) analysis showed that P. oxalicum SL2 could reduce the toxicity of Cr(VI) by synthesizing cysteine (Cys) and reduced glutathione (GSH). The decrease of thiol compounds (Cys and GSH) in P. oxalicum SL2 mycelia treated with SO 4 2− proved the alleviation of oxidative stress. In conclusion, exogenous Ca2+ could reduce the damage of Cr(VI) to P. oxalicum SL2 by maintaining the integrity of cell wall, and the addition of SO 4 2− alleviated the Cr(VI) toxicity to P. oxalicum SL2, thus accelerating the reduction of Cr(VI). [ABSTRACT FROM AUTHOR]

A new type of fault current limiter (FCL) is proposed based on the triggered vacuum switch (TVS). The TVS-based FCL (TFCL) is mainly composed of a capacitor, a current-limiting reactor connected with the capacitor in series, and a TVS connected with the capacitor in parallel. With TVS at the “off” or “on” state, the whole TFCL behaves as conventional series compensation or fault current limitation, respectively. Compared with other types of FCLs, such as superconductivity, thyristor/GTO-based FCL, TFCL is distinguished by its characteristics, such as high capacity, loss free, and low price. The digital simulation and prototype experiment based on the LC resonant test circuit show that it is feasible to develop TFCL [ABSTRACT FROM PUBLISHER]

This letter presents a new technique for generator protection. The fault-generated transient current signals are detected using a multichannel transient detection unit, then the spectral energies at different frequency bands are extracted and compared to discriminate between internal and external faults. Simulation results show that the scheme demonstrates good sensitivity to low-level and interturn faults [ABSTRACT FROM PUBLISHER]