Effect of short-term pig slurry amendment of soil on humified organic matter and its relationship with the dynamics of heavy metals and metals uptake by plants.

The impact of pig slurry (PS) application on the structural dynamics of humic substances (HS) and on the mobility of Cu, Zn, Ni, and Pb in a dystrophic Red Nitosol planted with winter forage grasses was evaluated. After four PS applications, the humic acids (HA) and fulvic acids (FA) were characterized by spectroscopy techniques allied to chemometrics methods. The metals contents in soil, in HS and in the tissues of plant were quantified. PS application increases the total organic carbon, especially the nonhumic carbon, which contribute to increase FA content. The carbon in FA and HA increases with the highest PS dose applied, especially aliphatic structures in FA and aromatic structures in HA. The amount of Pb and Cu in FA and HA increases respectively, as well as Cu, Zn, Ni, and Pb bioavailable. PS applications increase the biomass production in grasses and the metals content accumulated in the tissues. Our study shows that the PS application modifies the structure of SOM, incorporating fragments, and modifying its dynamics, which regulates the dynamics and the accumulation of metals in soils and plants. The association of metals with soluble structures seems to inactivate their toxicity and does not affect plant growth.

Cascade Synthesis of New Indole-Containing Pentacyclic Scaffolds Mediated by Aryl and Iminyl Radicals.

A five-step approach, starting from simple 1,5-disubstituted indoles, has been implemented for the synthesis of diversely substituted indole-pyrido-indene pentacyclic compounds up to 54 % yield via domino radical-mediated processes in the presence of the radical reagents DLP/TTMSS and AIBN/TTMSS. Reactions proceeded with diverse key starting radical cyano-precursors strategically synthesized which were subsequently transformed into the target pentacyclic compounds through an aryl/iminyl radical-mediated domino reactions sequence. In addition to the routine spectroscopic techniques, the structure of radical precursors, as well as, the target pentacyclic products were unequivocally established by single crystal X-ray diffraction, confirming the effectiveness of the proposed synthetic sequence.

Design, synthesis and crystallographic study of novel indole-based cyano derivatives as key building blocks for heteropolycyclic compounds of major complexity.

A four-stage reaction sequence has been designed and developed for the synthesis of highly functionalized enolate esters as key building blocks for the synthesis of novel heteropolycyclic compounds of potential pharmaceutical value. The sequence starts with simple commercially available indoles and proceeds via 3-(indol-3-yl)-3-oxopropanenitriles, which react with 2-bromobenzaldehyde to form the corresponding chalcones; these are readily reduced to dihydrochalcones, which are in turn acylated to form the enolate esters. The compounds in this sequence have been characterized by IR and 1H and 13C NMR spectroscopy, by mass spectrometry and by elemental analysis. The molecular and supramolecular structures are reported for representative examples, namely (E)-3-(2-bromophenyl)-2-(1-methyl-1H-indole-3-carbonyl)acrylonitrile, C19H13BrN2O, (Ib), (2RS)-2-(2-bromobenzyl)-3-(1-methyl-1H-indol-3-yl)-3-oxopropanenitrile, C19H15BrN2O, (IIb), and (2RS)-3-(1-benzyl-1H-indol-3-yl)-2-(2-bromobenzyl)-3-oxopropanenitrile, C25H19BrN2O, (IIc), the latter two of which crystallize with Z' = 2, and (E)-1-(1-acetyl-1H-indol-3-yl)-3-(2-bromophenyl)-2-cyanoprop-1-en-1-yl acetate, C22H17BrN2O, (III), and (E)-1-(1-benzyl-1H-indol-3-yl)-3-(2-bromophenyl)-2-cyanoprop-1-en-1-yl benzoate, C32H23BrN2O, (IV). The structure of the related chalcone (E)-2-benzoyl-3-(2-bromophenyl)prop-2-enenitrile, (V), has been redetermined at 100 K, where it is monoclinic, as opposed to the triclinic form reported at ambient temperature.

Property enhancement of soy protein isolate-based films by introducing POSS.

To enhance the mechanical and water-resistant properties of soy protein isolate (SPI) based films, hydrophobic TriSilanolPhenyl polyhedral oligomeric silsesquioxanes (POSS) was incorporated to modify the SPI films. POSS has three SiOH groups in a molecular, which is employed to cross-link SPI with the help of 3-glycidoxypropyltrimethoxysilane (GPTMS). POSS is a structure of eight phenol groups, playing a critical role in improving the physical and mechanical properties. The X-ray diffraction (XRD) and attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FT-IR) were used to characterize the films. The degree of reaction of SiOH groups in the POSS was estimated to be 53.0% according with the absorbance of ATR FT-IR spectra. Although the elongation at break was reduced by 52.6%, the tensile modulus, tensile strength and 10% offset yield strength were significantly increased by 86.6%, 34.0% and 56.8%, respectively, due to the cross-linking reactions among SPI, GPTMS and POSS. The results of water-resistant tests showed that the 24-hour water absorption was dramatically reduced by 54.7%.

Assessment of the Use of Natural Materials for the Remediation of Cadmium Soil Contamination.

Rice plants accumulate cadmium (Cd2+) within the grain, increasing the danger of human exposure. Natural materials have been used in soil remediation, but few studies have examined the risks (based on the bioavailability of these metals to plants) of using these materials, so the practice remains controversial. In the present study, we evaluated the effectiveness of biochar produced from sugarcane bagasse, vermicompost (VC), vermicompost solid residue (VCR) and humin for remediation of Cd2+-contaminated soils. We characterized the interactions between these materials and Cd2+ and evaluated their capacity to alter Cd2+ availability to rice plants. Our results show that under the conditions in this study, biochar and humin were not effective for soil remediation. Although biochar had high Cd2+ retention, it was associated with high Cd2+ bioavailability and increased Cd2+ accumulation in rice plants. VC and VCR had high Cd2+ retention capacity as well as low Cd2+ availability to plants. These characteristics were especially notable for VCR, which was most effective for soil remediation. The results of our study demonstrate that in the tested materials, the bioavailability of Cd2+ to plants is related to their structural characteristics, which in turn determine their retention of Cd2+.

Hybrid boron nitride-natural fiber composites for enhanced thermal conductivity.

Thermal conductivity was dramatically increased after adding natural fiber into hexagonal boron nitride (hBN)/epoxy composites. Although natural fiber does not show high-thermal conductivity itself, this study found that the synergy of natural fiber with hBN could significantly improve thermal conductivity, compared with that solely using hBN. A design of mixtures approach using constant fibers with increasing volume fractions of hBN was examined and compared. The thermal conductivity of the composite containing 43.6% hBN, 26.3% kenaf fiber and 30.1% epoxy reached 6.418 W m-1 K-1, which was 72.3% higher than that (3.600 W m-1 K-1) of the 69.0% hBN and 31.0% epoxy composite. Using the scanning electron microscope (SEM) and micro computed tomography (micro-CT), it was observed that the hBN powders were well distributed and ordered on the fiber surfaces enhancing the ceramic filler's interconnection, which may be the reason for the increase in thermal conductivity. Additionally, the results from mechanical and dynamic mechanical tests showed that performances dramatically improved after adding kenaf fibers into the hBN/epoxy composite, potentially benefiting the composite's use as an engineered material.

Fibroblast growth factor decreases locomotor activity in rats.

The spontaneous locomotor behavior of rats receiving subcutaneous administration of either acidic or basic fibroblast growth factors was recorded in an activity cage. We report that doses between 1 and 100 micrograms/kg significantly decreased the horizontal and vertical activity, as well as the exploratory and stereotypy behavior of the rats. These effects of fibroblast growth factors seem to be specific since (i) they were cancelled by protein hydrolysis and anti-fibroblast growth factor antibodies, (ii) they were unrelated to their hypotensive activity and (iii) they were not attributable to their high structural similarity with the cytokine interleukin-1. Thus fibroblast growth factors did not show any thermogenic activity, did not affect the hypothalamic output of corticotropin-releasing factor and did not change the plasma levels of corticosterone. Pretreatment of the rats with a specific inhibitor of brain nitric oxide synthase prevented the effects of fibroblast growth factors, suggesting the involvement of nitric oxide in these behavioral modifications. Our results contribute to the accumulating evidence describing non-mitogenic activities of fibroblast growth factors.