Mechanisms Controlling Arsenic Uptake in Rice Grown in Mining Impacted Regions in South China

<div><p>Foods produced on soils impacted by Pb-Zn mining activities are a potential health risk due to plant uptake of the arsenic (As) associated with such mining. A field survey was undertaken in two Pb-Zn mining-impacted paddy fields in Guangdong Province, China to assess As accumulation and translocation, as well as other factors influencing As in twelve commonly grown rice cultivars. The results showed that grain As concentrations in all the surveyed rice failed national food standards, irrespective of As speciation. Among the 12 rice cultivars, “SY-89” and “DY-162” had the least As in rice grain. No significant difference for As concentration in grain was observed between the rice grown in the two areas that differed significantly for soil As levels, suggesting that the amount of As contamination in the soil is not necessarily the overriding factor controlling the As content in the rice grain. The iron and manganese plaque on the root surface curtailed As accumulation in rice roots. Based on our results, the accumulation of As within rice plants was strongly associated with such soil properties such as silicon, phosphorus, organic matter, pH, and clay content. Understanding the factors and mechanisms controlling As uptake is important to develop mitigation measures that can reduce the amount of As accumulated in rice grains produced on contaminated soils.</p></div

Cultivar means for each parameter as observed in Renhua and Lechang.

<p>Results are presented as arithemic mean ± SD; means within a row for a certain genotype grown in Lechang or Renhua followed by different letters are significantly different at the 0.05 level; the comparisons are based on estimated marginal means.</p><p>Cultivar means for each parameter as observed in Renhua and Lechang.</p

Descriptive statistics of soil properties of Renhua and Lechang.

<p>Results are presented as arithemic mean ± SD; probability indicates the differences between Renhua and Lechang; n represents Number of samples; the <i>italic</i> number represents the minimum value of the characteristic in all the 28 surveyed samples; the <b>bold</b> number represents the maximum value of the characteristic in all the 28 surveyed samples.</p><p>Descriptive statistics of soil properties of Renhua and Lechang.</p

Plot of the first two principal components from Principal Component Analysis (PCA).

<p>The PCA was performed with As, Fe and Mn in DCB extracts, total As in soil, Fe₂O₃ and Mn₂O₃, available phosphorus (AP) and Si (ASi), selected soil properties, As in rice tissues.</p

Location map of the study area and distribution of sampling sites.

<p>Location map of the study area and distribution of sampling sites.</p

Descriptive statistics of rice plant accumulation and transfer factors.

<p>Results are presented as arithemic mean ± SD; probability indicates the differences between Renhua and Lechang; n represents Number of samples; the <i>italic</i> number represents the minimum value of the characteristic in all the 28 surveyed samples; the <b>bold</b> number represents the maximum value of the characteristic in all the 28 surveyed samples.</p><p>Descriptive statistics of rice plant accumulation and transfer factors.</p

A Fully Automated Online Enrichment and Separation System for Highly Reproducible and In-Depth Analysis of Intact Glycopeptide

A fully automated online enrichment and separation system for intact glycopeptides, named AutoGP, was developed in this study by integrating three different columns in a nano-LC system. Specifically, the peptide mixture from the enzymatic digestion of a complex biological sample was first loaded on a hydrophilic interaction chromatography (HILIC) column. The nonglycopeptides in the sample were washed off the column, and the glycopeptides retained by the HILIC column were eluted to a C18 trap column to achieve an automated glycopeptide enrichment. The enriched glycopeptides were further eluted to a C18 column for separation, and the separated glycopeptides were eventually analyzed by using an orbitrap mass spectrometer (MS). The optimal operating conditions for AutoGP were systemically studied, and the performance of the fully optimized AutoGP was compared with a conventional manual system used for glycopeptide analysis. The experimental evaluation shows that the total number of glycopeptides identified is at least 1.5-fold higher, and the median coefficient of variation for the analyses is at least 50% lower by using AutoGP, as compared to the results acquired by using the manual system. In addition, AutoGP can perform effective analysis even with a 1-μg sample amount, while a 10-μg sample at least will be needed by the manual system, implying an order of magnitude better sensitivity of AutoGP. All the experimental results have consistently proven that AutoGP can be used for much better characterization of intact glycopeptides

SO₂ Poisoning of the NH₃‑SCR Reaction over Cu-SAPO-34: Effect of Ammonium Sulfate versus Other S‑Containing Species

SO₂ poisoning of NH₃-SCR over Cu-SAPO-34 was studied, specifically to evaluate the forms/states of stored S and the effect of such species on low-temperature NO_<i>x</i> reduction activity. Two primary sulfur species types were observed and were found to be interchangeable depending on whether NH₃ was available or not. In one case both ammonium sulfate and Cu sulfate species could be present and in the other only Cu sulfate species. Cu sulfate, in the absence of ammonia, was found in three different states/forms, identified by three desorption features during temperature-programmed desorption (TPD) experiments. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of NO adsorption was used to investigate the nature and accessibility of the Cu species before and after sulfate formation, without the interference of ammonium sulfate; these data revealed that the Cu²⁺ inside the six-membered rings was completely blocked by sulfur and that the nature of the [CuOH]⁺ close to the eight-membered ring changed. In comparing the effect of different forms of S on low-temperature NO_<i>x</i> reduction activity, ammonium sulfate had the greatest impact on performance loss. Interestingly, the results also show that ammonium sulfate can actually play a role as a SCR reactant, likely analogous to the mechanism involving ammonium nitrate. Ammonium sulfate decomposes at temperatures as low as ∼300–350 °C, whereas higher temperatures (>480 °C) were needed to desorb other S-containing species. This appears favorable, as NH₃ can react with preadsorbed sulfur on the catalyst to form ammonium sulfate, which decomposes at lower temperatures in comparison to the other sulfate forms

Renalase inhibited renal apoptosis induced by Contrast.

<p>A, representative renal sections from normal control, Ioversol, Ioversol+vehicle, and Ioversol+renalase groups (TUNEL staining, 400x). B, quantitative analysis of renal apoptosis. C, renal Capase-3 activity. Animal number in each group is 6. **P<0.01, vs CTL group; #P<0.05, vs Veh group; ▲▲P<0.01, vs CTL (One-way ANOVA with Sidak compensation for the analysis of apoptosis, Kruskal-Wallis with Dunn’ compensation for Caspase-3).</p

Renalase decreased levels of serum creatinine, blood urea nitrogen and histological injuries in CIN rats.

<p>**P<0.01, vs CTL;</p><p>^#P<0.05, vs Iov+Veh;</p><p>^##P<0.01, vs Iov+Veh;</p><p>^▲P<0.05, vs CTL;</p><p>^▲▲P<0.01, vs CTL (One-way ANOVA with Sidak compensation)</p><p>Renalase decreased levels of serum creatinine, blood urea nitrogen and histological injuries in CIN rats.</p