Predicting the Sorption of Aromatic Acids to Noncarbonized and Carbonized Sorbents

Approaches based on the octanol–water partition coefficient are commonly used to describe sorption of neutral organic compounds in environmental systems, but they are not suitable for organic acids, which can dissociate to form anions. We here investigate the applicability of an alternative approach based on the pH-dependent distribution ratio (<i>D</i>_OW) to describe sorption of aromatic acids to sorbents representing different degrees of carbonization. Sorption isotherms for four structurally similar acids ((2,4-dichlorophenoxy)­acetic acid (2,4-D), 4-chloro-2-15 methylphenoxy)­acetic acid (MCPA), 4-(2,4-dichlorophenoxy)­butanoic16 acid (2,4-DB), and 5-chloro-2-(2,4-dichlorophenoxy)­phenol (triclosan)) were measured for 15 sorbents: fresh and carbonized wood shavings, pig manure, sewage sludge, carbon nanotubes, and activated carbon. Dissociation greatly affected the sorption of all acids. Sorption coefficients measured in the high pH range indicated that sorption of the anions ranged over several orders of magnitude and should not be neglected. Sorption trends for all sorbates and carbonized sorbents could be very well described by a single regression equation that included <i>D</i>_OW of the sorbate and the specific surface area of the sorbent (<i>R</i>² > 0.89)

Expression of Islet-1 protein in mouse embryonic and neonatal hearts.

<p>A representative Western blotting showed that Islet-1 was dynamically expressed in the embryonic hearts. The expression of Islet-1 in mouse embryonic hearts was significantly higher on E14.5 than that on E11.5, E17.5, and neonatal mice. * <i>p</i> < 0.05 (n=3).</p

Acetylation level of histone H3 in cardiac progenitor cells after inhibiting Islet-1 expression.

<p>Western blotting analysis showed that detectable level of histone H3 acetylation was present in cardiac progenitor cells, and was not significantly changed when Islet-1 expression was inhibited (A, <i>p</i>>0.05, n=3). However, the DNA quantity of Mef2c in the promoter region immunoprecipitated with acH3 antibody was significantly decreased in the cells transfected with Islet-1 RNAi as compared with the controls, while no difference was observed in the DNA quantity of GATA4 and Tbx5 in the cells (B). *<i>p</i><0.05, n=3. </p

Transcriptional expression of cardiac development-related transcription factors in cardiac progenitor cells after lentivirus transfeciton with Islet-1 RNAi.

<p>Quantitative RT-PCR analysis showed the mRNA level for Islet-1 was dramatically reduced in cardiac progenitor cells when transfected with Islet-1 RNA interference vector to inhibit Islet-1 (A). The mRNA levels for Mef2c and Tbx5 were significantly reduced in the cells when Islet-1 expression was inhibited with RNAi as compared with the controls. There was no significant difference in GATA4 mRNA level in the cells with Islet-1 knockdown with RNAi (B). *<i>p</i> < 0.05, n=3-5. </p

Interaction of p300 with the promoter regions of Mef2c, GATA4 and Tbx5 in cardiac progenitor cells.

<p>The DNA quantity of Mef2c in the promoter regions immunoprecipitated using p300 antibody was significantly decreased in the cells transfected with Islet-1 RNAi as compared with the controls. However, no difference in the DNA quantity of GATA4 and Tbx5 was observed in the cells with or without transfection with Islet-1 RNAi. * <i>p</i> < 0.05, n=3.</p