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Effects of incorporation of the biochars generated from rice straw and peanut straw at different temperatures on soil pH and Pb(II) adsorption were investigated with two variable charge soils. The soil pH increased by 1.04-3.00 units, and the increase in soil pH increased with the rise of pyrolysis temperature of the biochar. Results from adsorption isotherm experiments indicated that the incorporation of the biochar enhanced the adsorption of Pb(II) by two soils. The adsorption of Pb(II) was increased by 12.6% -57.6%, when the initial concentration of Pb(II) is 2 mmol x L(-1). The adsorption also increased with rising pH. Freundlich and Langmuir equations can be used to fit the adsorption isotherms of Pb(II), but the Freundlich equation fitted the adsorption data better, the r-values are above 0.94. Soils incorporated with peanut straw char have a greater adsorption capacity for Pb(II) than these incorporated with rice straw char as predicted by the parameters of k and Q(m) in Freundlich and Langmuir equations, respectively. The biochars generated at 400 degrees C have a greater enhancement on Pb(II) adsorption by soils than 300 degrees C and 500 degrees C. Desorption results showed that the desorption of Pb(II) for the treatments with biochar added was greater than that for the control, but the amount of desorbed Pb(II) was much lower than that of adsorbed Pb(II). These results suggested that the enhanced adsorption of Pb(II) by incorporation of the biochars involved at least two mechanisms: electrostatic adsorption and non-electrostatic adsorption.

Reduction capacity (RC) has been recognized as an important parameter for evaluating the redox role of humic acid (HA). Thus, for understanding the capacity of HA for the reduction of mercury (Hg2+), chemical reduction capacity (CRC), microbial reduction capacity (MRC) and native reduction capacity (NRC) for mercury reduction by three types of HAs extracted from various sources (SH, TJ and JY) were measured respectively, following the pre-treatment of the HA samples by saturated hydrogen oscillation, soil solution incubation and the control (without any pretreatment). Three electron acceptors including mercuric chloride (HgCl2), mercuric nitrate [Hg(NO3)3] and ferric citrate (FeCit) as a reference were adapted respectively based on the Fe3+ reduction method. The principal results indicated that: (1) the capacity of HA for the reduction of Hg was significantly affected by various electron acceptors, with the RC values obtained under FeCit condition were all greatly higher than those in the conditions of Hg(NO3)2 and HgCl2, which suggested that the RC obtained using Fe3+ reduction method could exaggerate the actual capacity of HA for the reduction of Hg2+; (2) significant differences existed for the reduction capacity of Hg2+ by different HAs, with those of JY were the highest, which were (0.95 +/- 0.03) mmol(c) x mol(-1) (NRC), (5.95 +/- 0.63) mmol(c) x mol(-1) (CRC) and (6.26 +/- 0.51) mmol(c) x mol(-1) (MRC) respectively; (3) HA in solution forms had approximately 100% - 691.67% higher reduction capacity than those as solid forms. Meanwhile, through comparison of the differences among three RC indices, higher CRC and MRC values than NRC were observed, but no significant difference between CRC and MRC was concluded. Thus, CRC may not be applicable to comprehensively represent the real reduction capacity of HA for Hg reduction under microbial condition.

Objective: The effect of vascular endothelial growth factor(165) (VEGF(165)) on intracellular free magnesium ([Mg(2+)](i)) and the relationship between Mg(2+) and angiogenesis in human umbilical vein endothelial cells (HUVECs) were investigated in this study., Methods: [Mg(2+)](i) in HUVECs loaded with fluorescent magnesium indicator mag-fura-2 were quantitatively detected with the use of intracellular cation measurement system. HUVECs were obtained from normal fetus and cultured in M199 with 0.2 fetal bovine serum. The angiogenesis effects of VEGF(165) were observed in presence of 0 mmol/L, 1 mmol/L or 2 mmol/L of extracellular Mg(2+)., Results: VEGF(165) significantly increased [Mg(2+)](i) in a dose-dependent manner independent of extracellular Mg(2+), Na(+) and Ca(2+) and this effect could be blocked by pretreatment with VEGF(165) receptor-2 (KDR) inhibitor (SU1498). The angiogenesis induced by VEGF(165) was significantly inhibited cells with 0 mmol/L extracellular Mg(2+), the angiogenesis effects of VEGF(165) were similar in cells with 1 mmol/L and 2 mmol/L extracellular Mg(2+) and these effects could be blocked by SU1498., Conclusions: These results suggest that the [Mg(2+)](i) increase induced by VEGF(165) originates from intracellular Mg(2+) pools and promotes angiogenesis via KDR-dependent signaling pathways.

In this paper, biosorption efficiency of heavy metals by bacteria isolated from activated sludge was tested. It was shown that Pseudomonas pseudoalcaligenes and Micrococcus luteus GC subgroup B had high biosorption capacities for Cu(II) and Pb(II) ions. The adsorption of the two ions on Pseudomonas pseudoalcaligenes and Micrococcus luteus GC subgroup B exhibited Langmuir adsorption behavior with regression coefficient of 0.99. The pH value was the most important effect factor on biosorption of metal ions. The biosorption kinetic curves of Cu(II) and Pb(II) ions by cells showed two processes: rapid sorption on cell surface and slowly longer-term transformation into cells. Cu(II) ion can be desorbed effectively from cells of Micrococcus luteus GC subgroup B.

Using planar lipid bilayer formed by lecithin and cholesterol (20 and 5 mg/ml respectively in N-decane) the channel-forming activity of the membrane active polypeptide B(BMAP B) from the venom of Bungarus fasciatus was investigated. Under the existence of a voltage or a salt concentration gradient between two sides of the bilayer, unit conductance fluctuation and a decrease in steady state resistance accompanying BMAP B incorporation and channel formation were observed. By measuring the reversal potential in an asymmetric solution, the selectivity of the BMAP B-channel was estimated having a value of PK/PC1 = 1.4. Divalent cations, such as Ba2+, Ca2+ inhibited the channel activity as they did in biomembranes. These data might provide an explanation for the depolarizing effect of the membrane active polypeptide on the native membranes.