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  • Author: Paulo H. S. Moreira x
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Open access

Paulo H. S. Moreira, Martinus Th. van Genuchten, Helcio R. B. Orlande and Renato M. Cotta

Abstract

In this study the hydraulic and solute transport properties of an unsaturated soil were estimated simultaneously from a relatively simple small-scale laboratory column infiltration/outflow experiment. As governing equations we used the Richards equation for variably saturated flow and a physical non-equilibrium dual-porosity type formulation for solute transport. A Bayesian parameter estimation approach was used in which the unknown parameters were estimated with the Markov Chain Monte Carlo (MCMC) method through implementation of the Metropolis-Hastings algorithm. Sensitivity coefficients were examined in order to determine the most meaningful measurements for identifying the unknown hydraulic and transport parameters. Results obtained using the measured pressure head and solute concentration data collected during the unsaturated soil column experiment revealed the robustness of the proposed approach.

Open access

Paulo H. B. França, Edeildo F. Da Silva-Júnior, Pedro G. V. Aquino, Antônio E. G. Santana, Jamylle N. S. Ferro, Emiliano De Oliveira Barreto, Cláudia Do Ó Pessoa, Assuero Silva Meira, Thiago M. De Aquino, Magna S. Alexandre-Moreira, Martine Schmitt and João X. De Araújo-Júnior

Abstract

Guanylhydrazones have shown promising antitumor activity in preclinical tumor models in several studies. In this study, we aimed at evaluating the cytotoxic effect of a series of synthetic guanylhydrazones. Different human tumor cell lines, by including HCT-8 (colon carcinoma), MDA-MB-435 (melanoma) and SF-295 (glioblastoma) were continuous exposed to guanylhydrazone derivatives for 72 hours and growth inhibition of tumor cell lines and macrophages J774 was measured using tetrazolium salt (MTT) assay. Compounds 7, 11, 16 and 17 showed strong cytotoxic activity with IC50 values lower than 10 μmol L−1 against four tumor cell lines. Among them, 7 was less toxic to non-tumor cells. Finally, obtained data suggest that guanylhydrazones may be regarded as potential lead compounds for the design of novel anticancer agents.