High-Frequency EPR Studies of New 2p-3d Complexes Based on a Triazolyl-Substituted Nitronyl Nitroxide Radical: The Role of Exchange Anisotropy in a Cu-Radical System.

Using the 1-(-tolyl)-1-1,2,3-triazole-4-(4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) (TlTrzNIT) radical and metal β-diketonate complexes [M(hfac)(HO)], where hfac is hexafluoroacetylacetonato, three new 2p-3d heterospin complexes were synthesized. Their structures were solved using single crystal X-ray diffraction data, and magnetic investigation was performed by DC and AC measurements and multifrequency EPR spectroscopy. Compounds and are isostructural complexes with molecular formula [M(TlTrzNIT)(hfac)] (M = Mn or Cu) while compound is the mononuclear [Co(TlTrzNIT)(hfac)] complex.

Combination of Water Quality Parameters and Bioassays for the Assessment of Two Rivers, Southern Brazil.

In the present study, water physicochemical and microbiological parameters, as well as bioassays using Allium cepa L. seeds and the fish species Astyanax jacuhiensis were used to assess the water quality of two rivers - Ilha River and Paranhana River -, located in southern Brazil. Water samples were collected at the source and mouth of the rivers and then, laboratory experiments were performed.

Potential use of distinct biomarkers (trace metals, micronuclei, and nuclear abnormalities) in a heterogeneous sample of birds in southern Brazil.

The analysis of metal concentrations in bird feathers and genotoxicity tests are tools used to evaluate anthropogenic impacts on ecosystems. We investigated the response of birds, used as bioindicators, to disturbances observed in three areas with distinctive environmental characteristics (natural, agricultural, and urban) in southern Brazil. For this purpose, we quantified metals (Mn, Cu, Cr, and Zn) in feathers and determined the number of micronuclei (MN) and other nuclear abnormalities (NA) in 108 birds from 25 species and 17 families captured in the study area.

Histopathological, genotoxic, and behavioral damages induced by manganese (II) in adult zebrafish.

Manganese is a metal often found as an environmental pollutant and very associated with neurological disorders when in high concentrations. However, little is known about the effects that this contaminant can cause when in environmentally relevant concentrations and occurrence, that is, much lower than those commonly studied. So, the aim of the study was to evaluate the effects that environmentally relevant concentrations of this metal would cause in different zebrafish organs (brain, liver, and blood).

Lanthanide chains containing the naphthalenyl nitronyl nitroxide radical.

In this contribution we report the synthesis, structure and magnetic properties of a family of lanthanide-based one dimensional compounds [Ln(hfac)(NaphNN)] , where Ln = Gd (1), Dy(2), Tb(3) and NaphNN is the nitronyl nitroxide (NN) radical 2-(1'-naphthalenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1-Imidazole-3-oxide-1-oxyl. The crystal structure reveals well isolated chains with a twofold helical axis. Magnetic investigation of the gadolinium(iii) chains showed relevant intrachain interactions between Gd-NN nearest neighbors and also Gd-Gd and NN-NN next nearest neighbors.

Magnetic Cationic Copper(II) Chains and a Mononuclear Cobalt(II) Complex Containing [Ln(hfac)] Blocks as Counterions.

Four new heterospin compounds with molecular formula {[Cu(hfac)(TlTrzNIT)][Ln(hfac)]} ·CH (Ln = Gd (1), Tb (2), or Dy (3)) and [Co(hfac)(TlTrzNIT)][Dy(hfac)] (4), where hfac is hexafluoroacetylacetonato and TlTrzNIT is the nitronylnitroxide radical 1-( m-tolyl)-1 H-1,2,3-triazole-4-(4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), were obtained. All structures were determined by single-crystal X-ray diffraction. In compounds 1-3, the TlTrzNIT radical is bridge-coordinated to copper(II) ions, leading to positively charged copper(II)-radical chains containing [Ln(hfac)] as counterions.

In situ monitoring of the Sinos River, southern Brazil: water quality parameters, biomarkers, and metal bioaccumulation in fish.

The Sinos River is an important water supply in Southern Brazil and receives industrial, agricultural, and domestic effluents which may affect aquatic biota. Water physicochemical and microbiological analyses, biomarker responses (scaled mass index (SMI), gill histopathology, and micronucleus and nuclear abnormality (MN and NA) frequencies), and metal bioaccumulation in muscle were assessed in the fish species Bryconamericus iheringii (Characidae) captured at three sampling sites (S1, S2, and S3) in four sampling periods. The mean values of five parameters (total phosphorus, thermotolerant coliforms, aluminum, iron, and lead) exceeded the limits established by the Brazilian legislation at the three sampling sites.