Influence of pH and Oxidation State on the Interaction of Arsenic with Struvite During Mineral Formation

Struvite (MgNH₄PO₄·6H₂O) precipitated from animal and human wastes may be a sustainable source of fertilizer. However, arsenic, present in some wastes, may be removed with struvite. Here the sorption of As with struvite during mineral formation at pH 8–11 was assessed. The yield of struvite increased with pH, and was highest at pH 10. For recovered struvite, XRD indicated reduced crystallinity and particle size, and FT-IR suggested less distortion of phosphate tetrahedra with increased pH. The As impurity did not affect the crystallinity or particle size, but did contribute to phosphate distortion. Sorption of As­(V) was observed at all pH values, and was highest at pH 10. As­(III) sorption was consistently lower than that of As­(V), but increased with pH. XAFS suggested coprecipitation of As­(V), and adsorption of As­(III) as the potential sorption mechanisms. Solids derived from As­(III) solutions exhibited dual mechanisms due to the partial oxidation of As­(III) to As­(V) in solution prior to sorption. For struvite recovery in the presence of As, optimizing the pH to improve yields may increase the As content. Adsorbed As­(III) could be removed prior to fertilizer application, however coprecipitated As­(V) will release upon mineral decomposition, linking its cycling to that of phosphorus

Free Energy Coupling between DNA Bending and Base Flipping

Free energy simulations are presented to probe the energetic coupling between DNA bending and the flipping of a central thymine in double stranded DNA 13mers. The energetics are shown to depend on the neighboring base pairs, and upstream C or T or downstream C tended to make flipping more costly. Flipping to the major groove side was generally preferred. Bending aids flipping, by pushing the system up in free energy, but for small and intermediate bending angles the two were uncorrelated. At higher bending angles, bending and flipping became correlated, and bending primed the system for base flipping toward the major groove. Flipping of the 6-4 pyrimidine-pyrimidone and pyrimidine dimer photoproducts is shown to be more facile than for undamaged DNA. For the damages, major groove flipping was preferred, and DNA bending was much facilitated in the 6-4 pyrimidine-pyrimidone damaged system. Aspects of the calculations were verified by structural analyses of protein–DNA complexes with flipped bases

sj-docx-2-pac-10.1177_18344909241226761 - Supplemental material for Sleep spindles consolidate declarative memory with tags: A meta-analysis of adult data

Supplemental material, sj-docx-2-pac-10.1177_18344909241226761 for Sleep spindles consolidate declarative memory with tags: A meta-analysis of adult data by Peiyao Chen, Chao Hao and Ning Ma in Journal of Pacific Rim Psychology</p

sj-docx-1-pac-10.1177_18344909241226761 - Supplemental material for Sleep spindles consolidate declarative memory with tags: A meta-analysis of adult data

Supplemental material, sj-docx-1-pac-10.1177_18344909241226761 for Sleep spindles consolidate declarative memory with tags: A meta-analysis of adult data by Peiyao Chen, Chao Hao and Ning Ma in Journal of Pacific Rim Psychology</p

Alkaline-Metal-Promoted Divergent Synthesis of 1‑Aminoisoquinolines and Isoquinolines

Alkaline-metal-promoted divergent syntheses of 1-aminoisoquinolines and isoquinolines have been reported involving 2-methylaryl aldehydes, nitriles, and LiN(SiMe3)2 as reactants. In addition, the three-component reaction of 2-methylaryl nitriles, aldehydes, and LiN(SiMe3)2 has been developed to furnish 1-aminoisoquinolines. This protocol features readily available starting materials, excellent chemoselectivity, broad substrate scope, and satisfactory yields

VPA, but not SB, caused an increase in the cytoplasmic Ca²⁺ level.

<p>(A) VPA caused an increase in the cytoplasmic Ca²⁺ level. The wild-type cells harboring <i>adh1</i>-GFP-19-AEQ (pKB6892) were grown to exponential phase, and then the cells were collected and treated as described in Materials and Methods. A 10µl volume of EMM or 10X stock of various concentration of VPA (A) or SB (B) was added into the 96-well plate, and the cells were delivered to the wells via the luminometer pump. The aequorin luminescence was followed for 4 hours. The luminescence, given as relative light units (RLU) s⁻¹, is plotted versus time. The data are representative of six independent experiments. (B) SB didn’t cause an increase in the cytoplasmic Ca²⁺ level. The experiments were performed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068738#pone-0068738-g004" target="_blank">Figure 4A</a> except that SB was used as stimulant instead of VPA. The data are representative of six independent experiments.</p

Genome-Wide Screening for Genes Associated with Valproic Acid Sensitivity in Fission Yeast

<div><p>We have been studying the action mechanisms of valproic acid (VPA) in fission yeast <i>Schizosaccharomyces pombe</i> by developing a genetic screen for mutants that show hypersensitivity to VPA. In the present study, we performed a genome-wide screen of 3004 haploid deletion strains and confirmed 148 deletion strains to be VPA sensitive. Of the 148 strains, 93 strains also showed sensitivity to another aliphatic acids HDAC inhibitor, sodium butyrate (SB), and 55 strains showed sensitivity to VPA but not to SB. Interestingly, we found that both VPA and SB treatment induced a marked increase in the transcription activity of Atf1 in wild-type cells. However, in <i>clr6-1</i>, a mutant allele the <i>clr6⁺</i> gene encoding class I HDAC, neither VPA- nor SB induced the activation of Atf1 transcription activity. We also found that VPA, but not SB, caused an increase in cytoplasmic Ca²⁺ level. We further found that the cytoplasmic Ca²⁺ increase was caused by Ca²⁺ influx from extracellular medium via Cch1-Yam8 channel complex. Altogether, our present study indicates that VPA and SB play similar but distinct roles in multiple physiological processes in fission yeast.</p></div

VPA and SB may function as HDAC inhibitor in fission yeast.

<p>(A) The Venn diagrams of VPA- or SB- sensitive strains. The SB-sensitive strains were completely included in VPA-sensitive strains. Of the 148 VPA-sensitive strains, 93 strains also showed sensitivity to SB, the other 55 strains only showed sensitivity to VPA. (B) Immunoblot analysis of histone acetylation. The wild-type cells and <i>clr6-1</i> mutants were cultured in YPD at 27°C for 10 hours to exponential phase. Then the cell extracts were subjected to electrophoresis using 11% polyacrylamide gel and were immunoblotted using Acetyl-histone H4 antibody set (Ac K5; Ac K8; Ac K12) to detect histone H4 acetylation. Endogenous levels of total histone H4 protein was used as a loading control and was immunoblotted using anti-histone H4 antibodies. (C) VPA and SB treatment increased histone H4 acetylation. The exponentially growing wild-type cells were divided into three equal portions. One portion is left without treatment and the other three portions were treated with 4 mM VPA, 60 mM SB or 20 µg/ml TSA for 20 minutes, respectively. Then the protein is extracted and immunoblotted as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068738#pone-0068738-g002" target="_blank">Figure 2A</a>.</p

Strains used in this study.

<p>Strains used in this study.</p