Carlos Pinheiro

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Cyanobacterial toxins have been regarded by some researchers as allelopathic substances that could modulate the growth of competitors. Nevertheless, often the concentrations of toxins used are too high to be considered ecologically relevant. In this work we tested the hypothesis that microcystin-LR (MC-LR) and cylindrospermopsin (CYN) at ecologically(More)
Worldwide, cyanobacterial blooms have been increasing in intensity and frequency, with toxic cyanobacteria sometimes dominant throughout the year in many freshwater bodies. Since the coexistence of more than one type of cyanotoxins in freshwater environments is a common phenomenon, studies on the joint effects of these toxins would be very useful. In this(More)
The structure of the Ts1 toxin from the Brazilian scorpion Tityus serrulatus was investigated at atomic resolution using X-ray crystallography. Several positively charged niches exist on the Ts1 molecular surface, two of which were found to coordinate phosphate ions present in the crystallization solution. One phosphate ion is bound to the conserved basic(More)
The gallium(III) complexes [Ga(2Am4DH)(2)]NO(3) (1), [Ga(2Am4Me)(2)]NO(3) (2) and [Ga(2Am4Et)(2)]NO(3) (3) were prepared with 2-pyridineformamide thiosemicarbazone (H2Am4DH) and its N(4)-methyl (H2Am4Me) and N(4)-ethyl (H2Am4Et) derivatives. The thiosemicarbazones were cytotoxic against malignant RT2 glioblastoma cells (expressing p53 protein) with IC(50)(More)
Toxic cyanobacteria and cyanotoxins have been pointed as important players in the control of phytoplankton diversity and species abundance, causing ecological unbalances and contamination of the environment. In vitro experiments have been undertaken to address the impact of toxic cyanobacteria in green algae. In this regard the aim of this work was to(More)
The purpose of this paper is to study static solution configuration which describes the magnetic monopoles in a scenary where the gravitation is coupled with Higgs, Yang-Mills and fermions. We are looking for analysis of the energy functional and Bogomol'nyi equations. The Einstein equations now take into consideration the fermions' contribution for(More)
– We present a 3-dimensional model for massive gravity with masses induced by topological (Chern-Simons) and Proca-like mass terms. Causality and unitarity are discussed at tree-level. Power-counting renormal-izability is also contemplated. It is well-known that the linearized Einstein Lagrangian is the only one that describes (consistently with locality,(More)
Tungsten oxide nanoparticles were synthesized via a sol-gel route using metallic tungsten as precursor, and were printed on a flexible electrode using inkjet printing in order to build solid-state electrochromic cells. Several spectroscopic techniques were used to characterize and compare tungsten oxide particles obtained from different origins. FTIR, Raman(More)
The purpose of this work is to present a model for 3D massive gravity with topological and higher-derivative terms. Causality and unitarity are discussed at tree-level. Power-counting renormalizability is also contemplated. The formulation of a quantum gauge theory for gravity is certainly one of the hardest tasks theoretical physics has been facing over(More)
We present a new concept for the design of a polymeric conducting material that combines the chemical versatility of an organic salt (ionic liquid) with the morphological versatility of a biopolymer (gelatin); the resulting 'ion jelly' can be applied in electrochemical devices, such as batteries, fuel cells, electrochromic windows or photovoltaic cells.