Heterogeneous Microtubules of Self-assembled Silver and Gold Nanoparticles Using Alive Biotemplates

<div><p>Microtubules were constructed by covering the fungus Aspergillus aculeatus sequentially with silver and gold nanoparticles, resulting in a stable hybrid mesostructured material that presented three distinct regions containing different combinations of silver and gold nanoparticles. These heterogeneities were determined by the hyphal growth since the impossibility to cover the dead fungus, which suggests the influence of the secondary metabolites produced by living fungus in the deposition mechanism.</p></div

Selligueain A isolated from green fronds and litter of <i>P</i>. <i>arachnoideum</i>.

<p>Selligueain A isolated from green fronds and litter of <i>P</i>. <i>arachnoideum</i>.</p

Relative frequencies (%) of the size classes of sesame (<i>S</i>. <i>indicum</i>) seedling root metaxylem cells treated with different concentrations of selligueain A.

<p>Relative frequencies (%) of the size classes of sesame (<i>S</i>. <i>indicum</i>) seedling root metaxylem cells treated with different concentrations of selligueain A.</p

Early growth inhibition^a of sesame (<i>S</i>. <i>indicum</i>) seedlings treated with different concentrations of selligueain A.

<p>Early growth inhibition<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0161670#t001fn003" target="_blank">^a</a> of sesame (<i>S</i>. <i>indicum</i>) seedlings treated with different concentrations of selligueain A.</p

Chlorophyll a (C_a), chlorophyll b (C_b), and total chlorophyll (C_{a + b}) contents^a of photosynthetic cotyledons of sesame (<i>S</i>. <i>indicum</i>) seedlings treated with different concentrations of selligueain A.

<p>Chlorophyll a (C_a), chlorophyll b (C_b), and total chlorophyll (C_{a + b}) contents<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0161670#t003fn002" target="_blank">^a</a> of photosynthetic cotyledons of sesame (<i>S</i>. <i>indicum</i>) seedlings treated with different concentrations of selligueain A.</p

Inhibition of wheat (<i>T</i>. <i>aestivum</i>) coleoptile fragment elongation in the presence of selligueain A isolated from <i>P</i>. <i>arachnoideum</i> or the herbicide Logran at different concentrations.

<p>Vertical bars show standard deviation. Values marked with the letter a (<i>p</i> < 0.01) and b (0.01 < <i>p</i> < 0.05) are significantly different from those of the negative control according to Welch's test.</p

HPLC-PDA chromatograms of the extracts of soil collected from under a <i>P</i>. <i>arachnoideum</i> patch.

<p>S: selligueain A standard; E1: ESQ-1 soil sample extract; E2: ESQ-2 soil sample extract; E3: ESQ-3 soil sample extract; E4: ESQ-4 soil sample extract; 1: selligueain A peak.</p

Inhibition of wheat (<i>T</i>. <i>aestivum</i>) coleoptile fragment elongation in the presence of the EtOAc extracts fractions of <i>Pteridium arachnoideum</i> green fronds and litter and the herbicide Logran in different concentrations.

<p>(A) and (B): Green frond fractions; (C): Litter fractions. Black columns, 0.8 mg.mL⁻¹; gray columns, 0.4 mg.mL⁻¹; white columns, 0.2 mg.mL⁻¹. Vertical bars indicate standard deviation. Values marked with the letter a (<i>p</i> < 0.01) or b (0.01 < <i>p</i> < 0.05) are significantly different from those of the negative control according to Welch's test.</p

Micrographies of root metaxylem cells of sesame (<i>S</i>. <i>indicum</i>) seedlings.

<p>20× magnification.</p

Diclofenac on Boron-Doped Diamond Electrode: From Electroanalytical Determination to Prediction of the Electrooxidation Mechanism with HPLC-ESI/HRMS and Computational Simulations

Using square-wave voltammetry coupled to the boron-doped diamond electrode (BDDE), it was possible to develop an analytical methodology for identification and quantification of diclofenac (DCL) in tablets and synthetic urine. The electroanalytical procedure was validated, with results being statistically equal to those obtained by chromatographic standard method, showing linear range of 4.94 × 10^–7 to 4.43 × 10^–6 mol L^–1, detection limit of 1.15 × 10^–7 mol L^–1, quantification limit of 3.85 × 10^–7 mol L^–1, repeatability of 3.05% (<i>n</i> = 10), and reproducibility of 1.27% (<i>n</i> = 5). The association of electrochemical techniques with UV-vis spectroscopy, computational simulations and HPLC-ESI/HRMS led us to conclude that the electrooxidation of DCL on the BDDE involved two electrons and two protons, where the products are colorful and easily hydrolyzable dimers. Density functional theory calculations allowed to evaluate the stability of dimers A, B, and C, suggesting dimer C was more stable than the other two proposed structures, ca. 4 kcal mol^–1. The comparison of the dimers stabilities with the stabilities of the molecular ions observed in the MS, the compounds that showed retention time (RT) of 15.53, 21.44, and 22.39 min were identified as the dimers B, C, and A, respectively. Corroborating the observed chromatographic profile, dimer B had a dipole moment almost twice higher than that of dimers A and C. As expected, dimer B has really shorter RT than dimers A and C. The majority dimer was the A (71%) and the C (19.8%) should be the minority dimer. However, the minority was the dimer B, which was formed in the proportion of 9.2%. This inversion between the formation proportion of dimer B and dimer C can be explained by preferential conformation of the intermediaries (cation-radicals) on the surface