Phosphorus Fractionation in Core Sediments from Haihe River Mainstream,China

Sediments from Haihe River mainstream, located in Xingjiaquan, Zhangjiazui, Tianjin, were collected and examined on the basis of P fractionation. SMT (standards, measurements and testing) procedure was adopted to investigate the changes in P concentration with depth in the core sediments collected from the different sampling sites of Haihe River mainstream. The relationships among different P fractions, such as exchangeable P (Ex-P), metal oxide bounded P (NaOH-P), organic matter and grain size, were also discussed. The results indicate that in both sites the rank order of P fractions was HCl-P > Organic P (OP) > NaOH-P > Ex-P in terms of their concentration. The Ex-P represented < 4% of the sediment total P, while the NaOH-P ranged 5–21%. The calcium bound phosphorus (HCl-P) showed considerable contribution (53–80%) to the sediment total P loads. Silt/clay sized sediments exhibited significantly higher concentrations of HCl-P and Ex-P in both sites. However, coarse-sand-sized sediments exhibited significantly higher concentrations of OP in both sites and NaOH-P in Xingjiaquan. Multivariate statistics were performed to identify the factors that influenced the sediment P.     

Assessment of the Mutagenicity of Sediments from Yangtze River Estuary Using Salmonella Typhimurium/Microsome Assay

Sediments in estuaries are of important environmental concern because they may act as pollution sinks and sources to the overlying water body. These sediments can be accumulated by benthic organisms. This study assessed the mutagenic potential of sediment extracts from the Yangtze River estuary by using the Ames fluctuation assay with the Salmonella typhimurium his (−) strain TA98 (frameshift mutagen indicator) and TA100 (baseshift mutagen indicator). Most of the sediment samples were mutagenic to the strain TA98, regardless of the presence or absence of exogenous metabolic activation (S9 induction by β-naphthoflavone/phenobarbital). However, none of the samples were mutagenic to the strain TA100. Thus, the mutagenicity pattern was mainly frameshift mutation, and the responsible toxicants were both direct (without S9 mix) and indirect (with S9 mix) mutagens. The mutagenicity of the sediment extracts increased when S9 was added. Chemical analysis showed a poor correlation between the content of priority polycyclic aromatic hydrocarbons and the detected mutagenicity in each sample. The concept of effect-directed analysis was used to analyze possible compounds responsible for the detected mutagenic effects. With regard to the mutagenicity of sediment fractions, non-polar compounds as well as weakly and moderately polar compounds played a main role. Further investigations should be conducted to identify the responsible components.     

Adsorption of Cu and Zn onto Mn/Fe Oxides and Organic Materials in the Extractable Fractions of River Surficial Sediments

The roles of the extractable components (Mn oxides, Fe oxides, and organic materials) of surficial sediments in controlling metals adsorption were investigated. Cu and Zn adsorptions were conducted before and after the surficial sediments extracted with hydroxylamine hydrochloride, an oxalate solution, and H ₂ O ₂ , respectively. The extraction removed target components with extraction efficiencies from 63 to 98%. Nonlinear regression analyses of Cu and Zn adsorptions based on the assumption of additive Langmuir adsorption isotherm were employed to estimate the relative contributions of sediment components to Cu and Zn adsorptions. The results indicate that the greatest contribution to total Cu and Zn adsorption to the surficial sediments on a molar basis was from Mn oxides in the extractable fractions. Both Cu and Zn adsorption capacities of Mn oxides exceeded those of Fe oxides by approximately one order of magnitude, fewer roles were attributed to the adsorption of organic material (OM), and the estimated contribution of the residual fraction to total Cu and Zn adsorption was insignificant. These information implied that the roles of metal oxides (Fe and Mn oxides) in the extractable form of the surficial sediments, especially Mn oxides, was the most important component in controlling heavy metal transportation in aquatic environments.     

CALUX Bioassay of Dioxin-Like Compounds in Sediments from the Haihe River,China

Chemically Activated LUciferase gene eXpression (CALUX) bioassay is a rapid, effective, and cheap method to analyze dioxin-like compounds (DLCs). Using this method, total levels of DLCs, including PCDD/Fs (polychlorinated dibenzo-p-dioxin and dibenzofurans) fraction and DL-PCBs (dioxin-like polychlorinated biphenyls) fraction, in extracts of sediments from the Haihe River, China, were determined. It was found that the levels of PCDD/Fs in the sediments from the Haihe River were tens of times to hundreds of times higher than those of DL-PCBs. The DLC levels in sediments in March 2005 approximated those in November 2006. The CALUX toxic equivalents (TEQs) of DLCs were independent of the total organic carbon (TOC) of sediments. Significant correlation was observed between the PCDD/Fs TEQs and DL-PCBs TEQs. The two fractions of some samples were also analyzed by HRGC/HRMS (high-resolution gas chromatography/high-resolution mass spectrometry) method. Significant statistical correlations were observed between the CALUX TEQs and HRGC/HRMS TEQs. The difference between TEF (toxic equivalent factor) and REP (relative potency) can explain most of the discrepancy between CALUX and HRGC/HRMS analysis. A high level of DLCs was found at the sites near the influx into Bohai Bay. The dioxin pollution might be associated with industrial activities of pentachlorophenol (PCP) in the adjacent area. More attention should be paid to the increase of DLC levels and further investigation should be done for this area.     

Species and Biogeochemical Cycles of Organic Phosphorus in Sediments From a River With Different Aquatic Plants Located in Huaihe River Watershed,China

The results of phosphorus fractionation in the sediments from a contaminated river containing different aquatic plants, analyzed by solution ³¹P-NMR for Organic Phosphorus, showed that the concentration of Inorganic Phosphorus dominated in all species and Organic Phosphorus accounted for over 20% of Total Phosphorus. In general, orthophosphate was dominant in all the sampling sites. The proportion of Organic Phosphorus accounting for the Total Phosphorus in the sediments with different plant decreased in the following order: Paspalum distichum > Typha orientalis > Hydrilla verticillata. Phosphorus-accumulation ability of Paspalum distichum was obviously stronger than Typha orientalis and Hydrilla verticillata. The Organic Phosphorus was in aquatic plants dominated by humic-associated P (Hu-P), which converted to Inorganic Ohosphorus more significantly in submerged plants than in emerged plants. The sediment dominated by Paspalum distichum abundantly accumulated Organic Phosphorus in the orthophosphate monoester fraction. The degradation and mineralization of orthophosphate monoester was the important source of high Inorganic Phosphorus concentration and net primary productivity in Suoxu River. The Organic Phosphorus derived from Typha orientalis and Hydrilla verticillata was dramatically converted to Inorganic Phosphorus when the environmental factors varied.     

Assessment of membrane protection by 31P-NMR effects of lidocaine on calcium-paradox in myocardium

In studying calcium paradox, perfused rat hearts were used to investigate the myocardial protective effects of lidocaine. Intracellular contents of phosphates were measured using the 31P-NMR method. In hearts reexposed to calcium, following 3 minute calcium-free perfusion, a rapid contracture occurred, followed by rapid and complete disappearance of intracellular phosphates with no resumption of cardiac function. In hearts where lidocaine was administered from the onset of the calcium-free perfusion until 2 minutes following the onset of reexposure to calcium, both intracellular phosphates and cardiac contractility were maintained. Therefore, it can be said that cell membranes were protected by lidocaine.     

Phosphorus Nutrition and the Intracellular Distribution of Inorganic Phosphate in Pea Root Tips: A Quantitative Study using31P-NMR

Pea plants (Pisum sativum L.) were supplied with external phosphatefor differing periods of time, so that their phosphorus statusvaried, and the intracellular distribution of inorganic phosphate(P₁) in the roots was examined by ³¹P nuclear magnetic resonance.Over the range of phosphorus nutrition investigated, the quantityof vacuolar P₁ per unit fresh weight of root tip changed considerably,whereas the quantity of cytoplasmic P₁ per unit fresh weightof root tip did not alter. The relative volumes of the cytoplasmand the vacuole in pea root tips seemed to be little affectedby differences in phosphorus nutrition, and this implied thatthe concentration of P₁ in the cytoplasm was kept almost constant,at a level estimated to be 18 mM. The rate of absorption of ³²P-labelled phosphate was negativelycorrelated with the vacuolar P₁ concentration, but there wasno clear correlation with the concentration of P₁ in the cytoplasm. Key words: Compartmentation, Cytoplasm, Vacuole, Concentration, Absorption     

Microbial Biomass and Community Composition Involved in Cycling of Organic Phosphorus in Sediments of Lake Dianchi,Southwest China

Organic phosphorus (P_o) was a major fraction of phosphorus (P) in sediments of lakes, and microbes were involved in most of its relevant biogeochemical cycling. Forms and quantification of P_o were investigated by sequential fractionation in 18 sediments of Lake Dianchi, Southwest China. Microbial biomass and community structure in these sediments were determined by phospholipid fatty acids (PLFAs). Distribution of P_o fractions were in the rank order that humic P_o > nucleic acid and polyphosphate > residual P > Ca-Al-P_o > Fe-P_o > sugar P_o > acid soluble P_o > H₂O-P_o. The recoveries of P_o and P_i in these detailed sequential fractions including residual P shows that the total contents of P_o in sediments of lakes were overestimated by the Standards, Measurements and Testing (SMT) protocol (ignition method). Microbial biomass including Gram-positive bacteria (14.4–20.0%), Gram-negative bacteria (32.7–38.4%), microeukaryotes (14.9–24.4%), aerobic bacteria (43.6–55.8%), anaerobic bacteria (0–2.9%) and type ? methanotrophs (17.6–24.4%) were assigned. Microbial mass and their composition were strongly correlated with H₂O-P_o, Fe-P_o, nucleic acid and polyphosphate, and humic P_o, though residual P was likely inert for microbes in sediments. The formation and degradation of P_o was closely related with microbial activities in sediments. These findings have implications for understanding the role of microbes on cycling of P_o and organic matter in sediments of lakes.     

Geochemical Speciation and Risk Assessment of Heavy Metals in Sediments of a River in Bangladesh

The surface sediment of a downstream river (Paira) connected to the marine ecosystems of the Bay of Bengal was assessed by sequential extraction technique. The objectives of this study were to evaluate the mobility and dynamics of heavy metals and their probable ecological risks. The results revealed high environmental risk of Cd due to higher availability in the exchangeable fraction (21%) and a considerable portion in the carbonate bound fraction due to the special affinity towards carbonate and co-precipitation with its minerals. Toxic metals like Cr, Ni, and Cd are of concern, and can occasionally be associated with adverse biological effects. The risk assessment code (RAC) suggests that the highest mobility of Cd poses a higher environmental risk and threat to the aquatic biota, as well.     

An Evaluation of a Technical Holding Time for the Preparation and Analysis of Hexavalent Chromium in Soils/Sediments

Chromium (Cr) is routinely measured during environmental investigations involving soils and other solid matrix sampling. Regulatory-approved analytical methods are available to extract and quantify total Cr in various environmental media. However, due to significant toxicity differences between trivalent [Cr(III)] and hexavalent [Cr(VI)] valences, it is compelling that the two can be quantitatively distinguished. SW-846 Method 3060A is an effective extraction technique for soluble and insoluble Cr(VI). Several regulatory-approved methods exist for quantitating the Cr(VI) in extracts or aqueous samples. Although a 6-month holding time for total Cr is not encumbering, investigators are challenged by the typical 24-h holding time (sample collection through analysis) for Cr(VI) in aqueous samples and the 24- to 96-h holding time range for solid matrix samples typically set by regulators. This research report addresses quantitating Cr(VI) in solid matrices. Using SW-846 Methods 3060A/7196A, a scientifically defensible basis has been established for designating a 30-day holding time for Cr(VI) extraction from solid matrices and a 7-day holding time for Cr(VI) analysis once solubilized in the alkaline digestate. The study results indicate that a 30-day holding time, from sample collection to preparation, and a 7-day holding time, from digestion to analysis, are appropriate for Cr(VI) analysis.     

Spatial and Temporal Assessment of Diazotroph Assemblage Composition in Vegetated Salt Marsh Sediments Using Denaturing Gradient Gel Electrophoresis Analysis

Abstract Diazotroph assemblage compositions were assessed in rhizosphere sediments from the tall and short form Spartina alterniflora growth zones over an annual cycle. Sediment cores were collected for DNA extraction and nitrogenase (acetylene reduction) activity assays, and porewater samples were analyzed for several chemical parameters in March, June, September, and December 1997. These data were collected to determine if within- or between-zone differences in the diazotroph assemblage composition correlated with differences in key environmental variables or acetylene reduction activity. Acetylene reduction rates differed between zones and within a zone over an annual period. Soluble sulfide concentrations were higher in the short form S. alterniflora zone on all dates except those in June and differed within both zones on different sample dates. nifH sequences were recovered from rhizosphere sediment DNA by PCR amplification using nifH specific primers. These amplimers were analyzed using denaturing gradient gel electrophoresis (DGGE), and the resulting patterns were compared by neural network and linear discriminant analyses. Ten prominent amplimers, four of which were apparent heteroduplexes, were observed. DGGE banding profiles showed minor differences among sampling dates and between sample zones, but the overall banding pattern was remarkably consistent. This reflects overall similarity between the amplifiable diazotroph assemblages in the tall and short S. alterniflora growth zones and substantial seasonal stability in assemblage composition. Received: 2 March 1999; Accepted: 4 May 1999     

小卫星区域MS31A等位基因特异MVR—PCR分析

用等位基因特异ＭＶＲ－ＰＣＲ技术能够对小卫星区域ＭＳ３１Ａ（Ｄ７Ｓ２１位点）位基因结构的多态性进行分析,在法医学个体识别上具有极其重要的作用。对１００名中国人无关个体ＭＤ３１Ａ５’端侧翼ＤＮＡ多态性进行分析,获得了其不同等位基因的频率和单倍体型的分布,结果表明８１．８％的 ＤＮＡ样品能够用等位基因特异ＭＶＲ－ＰＣＲ分析。     

Effect of Dietary Magnesium on Post Mortem Phosphocreatine Utilization in Skeletal Muscle of Swine: A Non-Invasive Study Using 31P-NMR Spectroscopy

The effect of dietary magnesium on the post mortem PCr (phosphocreatine) decay in muscle of heterozygote malignant hyperthermia pigs was studied after in vivo exposure to a combination of halothane and succinylcholine. The pigs were anaesthetized with halothane and succinylcholine was injected in the ear vein. Immediately after initiation of the depolarizing neuromuscular blocking effect of succinylcholine the animals were captive-bolt stunned. The PCr decay, reflecting ATP turnover, was followed in situ by 31P-NMR spectroscopy in the biceps femoris muscle for the subsequent 40-70 min post mortem. In 3 of the 4 experiments, the Mg-fed pig had a significantly reduced rate of PCr hydrolysis compared to the control animal. The mechanism of this magnesium effect is unknown.     

Composition of Microbial Communities in Sediments from Southern Baikal Containing Fe/Mn Concretions

Massive parallel sequencing of the 16S rRNA gene fragments was used to investigate the composition and diversity of microbial communities in sediments from Southern Baikal to a depth of 9 cm with 1-cm step. In the layers from the sediment surface to the lower border of oxygen penetration (2 cm), organotrophic bacteria with high similarity to the heterotrophic species Luteolibacter luojiensis constituted the largest fraction of the community. In the formation zone of Fe/Mn crusts (3–5 cm), Proteobacteria and Actinobacteria predominated in the community, while the share of Cyanobacteria was considerable. The lower reduced layers showed an increased contribution of the Bacteroidetes, while the shares of the taxa predominant in the higher layers remained significant. Analysis of archaeal 16S rRNA gene amplicons revealed predominance of the soil and aquatic Thaumarchaeota (Marine Group I lineage), which are involved in anaerobic ammonium oxidation, practically in all sediment layers. The buried oxidized layer (6–7 cm), where members of the uncultured Marine Benthic Group D lineage of the order Thermoplasmatales (Euryarchaeota) predominated, was an exception in this regard. Small numbers of archaea of the Baikal-1 lineages (below 1%) were observed in the communities from the 6–7 and 7–8 cm layers, while the archaea involved in anaerobic methane oxidation (including the ANME-2d group) were not detected.     

31P-NMR investigation of trimethylphosphine binding to [alpha Fe(II), beta Mn(II)] hybrid hemoglobin. A model for partially liganded species

31P-NMR of trimethylphosphine binding to the ferrous chains of a ([alpha Fe(II), beta Mn(II)]hemoglobin hybrid is employed to investigate partially liganded species. This study shows that at low pH (6.5), in the presence of inositol hexaphosphate, the resonance at 23.2 ppm (from H3PO4) is due to phosphine bonding to alpha-chains in the T quaternary state. At elevated pH (7.6), phosphine binding to the alpha-chains produces a resonance at 24.8 ppm which is associated with a T-to-R conversion. These findings are discussed in relation with our previous results on direct observation of intermediate ligation states of hemoglobin.     

Preparation and Properties of Nanocolloidal Rhenium Sulfide Solution for Lymphoscintigraphic Methods of Micrometastase Examination

A method for the preparation of a nanocolloidal solution of rhenium sulfide is proposed. It includes the following stages: interaction of ammonium perrhenate and sodium thiosulfate in an aqueous solution of gelatin in an acidic medium with heating to 70–80°C; neutralization to pH 7.0; dialysis against saline; desalination and concentrating by ultrafiltration. The resulting colloidal solution contains 85% of particles with an optimal size of 80–100 nm and can be used as a diagnostic tool for lymphoscintigraphy of sentinel lymph nodes in patients with cancer and other diseases.     

Distribution and Risk Assessment of Heavy Metals in Sediments of the Pearl River Estuary,Southern China

Sediment cores collected at six freshwater discharge outlets of the Pearl River Estuary were analyzed for metal (Al, Fe, Cr, Pb, and Cd) concentration and risk assessment. The contents of Cr, Pb, Fe, and Al in these samples were measured by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), and Cd was measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The result showed that the concentration ranged (in mg/kg dry weight) as follows: Al, 7,880–97,700; Fe, 30,100–51,900; Cd, 0.23–1.09; Cr, 48.7–109; Pb, 22.3–70.2; respectively. The sediments of different particle size were measured and the result showed that the pelitic fraction (< 0.05 mm) was more enriched in heavy metals. Cd and Pb showed a similar spatial distribution in the sediment, which reflected similar anthropogenic origins. In addition, the temporal distribution of Cr, Pb, and Cd showed a light increase from the 1970s to the 2000s. Furthermore, the enrichment factor (EF) and the geo-accumulation index (I_geo) were used to comprehensively evaluate the pollution degree of heavy metals. The findings will be useful in proposing measures for strategic environmental control in estuaries.     

Assessment of Heavy Metal Contamination in the Sediments of the Shuangtaizi Estuary Using Multivariate Statistical Techniques

In order to assess heavy metal pollution of sediment samples collected from Shuangtaizi estuary, contamination factor (CF) and multivariate statistical analyses, including principal component analysis (PCA), cluster analysis (CA) and correlation analysis, are carried out in this paper. CF confirms that Pb, Cu and Hg concentrations are very low and all fall within the range of background, while Zn and Cd demonstrate moderate contamination (in A10, A13, A15, A16 and A17 sites) and very high contamination (in A10, A13, A15 and A17 sites), respectively. The PCA indicates that four significant principal components (PCs) are extracted, explaining 88.959% of total variance, which suggests that Pb, Cu and Zn are mainly associated with organic carbon (OC). The result from CA is consistent with that obtained from PCA, classifying that the heavy metals in two clusters derive from different sources. Correlation analysis supports the conclusions from PCA and CA, elucidating the relationships between heavy metals and particle sizes of the sediments.     

Assessment of Heavy Metal Contamination in the Surrounding Soils and Surface Sediments in Xiawangang River,Qingshuitang District

Xiawanggang River region is considered to be one of the most polluted areas in China due to its huge amount discharge of pollutants and accumulation for years. As it is one branch of Xiang River and the area downstream is Changsha city, the capital of Hunan Province, the ecological niche of Xiawangang River is very important. The pollution treatment in this area was emphasized in the Twelfth Five-Year Plan of Chinese government for Xiang River Water Environmental Pollution Control. In order to assess the heavy metal pollution and provide the base information in this region for The Twelfth Five-Year Plan, contents and fractions of four heavy metals (Cd, Cu, Pb and Zn) covering both sediments and soils were analyzed to study their contamination state. Three different indexes were applied to assess the pollution extent. The results showed this area was severely polluted by the four heavy metals, and the total concentrations exceeded the Chinese environmental quality standard for soil, grade III, especially for Cd. Moreover, Cd, rated as being in high risk, had a high mobility as its great contents of exchangeable and carbonates fractions in spite of its relative low content. Regression analysis revealed clay could well explain the regression equation for Cd, Cu and Zn while pH and sand could significantly interpret the regression equation for Pb. Moreover, there was a significant correlation between Non-residual fraction and I_geo for all the four metals. Correlation analysis showed four metals maybe had similar pollution sources.     

Assessment and Refinement of Sample Preparation Methods for Deep and Quantitative Plant Proteome Profiling

A major challenge in the field of proteomics is obtaining high‐quality peptides for comprehensive proteome profiling by LC–MS. Here, evaluation and modification of a range of sample preparation methods using photosynthetically active Arabidopsis leaf tissue are done. It was found that inclusion of filter‐aided sample preparation (FASP) based on filter digestion improves all protein extraction methods tested. Ultimately, a detergent‐free urea‐FASP approach that enables deep and robust quantification of leaf and root proteomes is shown. For example, from 4‐day‐old leaf tissue, up to 11 690 proteins were profiled from a single sample replicate. This method should be broadly applicable to researchers working with difficult to process plant samples.