Extraction Kinetics of As(V) by Aliquat-336 Using Asymmetric PVDF Hollow-Fiber Membrane Contactors.

This work focuses on the study of the mass transfer of arsenic(V) through asymmetric polyvinylidene fluoride hollow-fiber membrane contactors using Aliquat-336 as an extractant. In the first part of this work, the fibers were prepared and characterized by SEM and by determining their thickness and porosity. From SEM pictures, an asymmetric structure was obtained that was characterized by an inner sponge-like structure and outer finger-like structure with a pore radius and porosity about 0.11 µm and 80%, respectively. In the second part, the prepared fibers were used as membrane contactors for the study of mass transfer of arsenic(V), investigating the effect of several parameters such as pH, temperature, and initial concentration of the feed. The overall mass transfer coefficient of As(V) was around 6 × 10⁻6 cm/s.

Expression of WISP3 and RhoC genes at mRNA and protein levels in inflammatory and noninflammatory breast cancer in Tunisian patients.

Previous studies have shown the expression WISP3 and RhoC in cell lines of inflammatory breast cancer (IBC). The aim in the current study was to compare the expression of both genes, in biopsy samples collected from Tunisian patients with localized or metastatic breast cancer and patients with IBC. We investigated 127 patients enrolled in Salah Azaiez Institute in Tunis. Using the RT-PCR, we showed the phenotype (WISP3-, RhoC+) is significantly associated with IBC tumors, while the (WISP3+, RhoC-)phenotype is mostly associated to non-IBC tumors. The frequencies of these tumor phenotypes are significantly different between these tumor groups (p = 10(- 7); relative risk or RR = 3.25; confidential interval or CI 95% = 1.90-5.53). Immunohistochemical test revealing the presence of WISP3 and RhoC proteins correlates with the expression in the biopsy of their encoding genes as detected by RT-PCR. In conclusion, it appears that WISP3 and RhoC genes expression status defines a molecular signature of IBC.

Simultaneous determination of Fe(III) and Al(III) by first-derivative spectrophotometry and partial least-squares (PLS-2) method - application to post-haemodialysis fluids.

Derivative spectrophotometry (graphical method) and partial least-squares regression (numerical method) methods were developed for the spectrophotometric multi-component analysis of post-haemodialysis fluids and synthetic mixtures containing Al(III) and Fe(III) without any chemical separation. The complexes of these metal ions with chrome azurol S were formed immediately at pH 5.5 and were stable for at least 3h. The graphical method is based on the use of first-derivative spectra for evaluation because working wavelength determination was more precise and spectral overlap was less than in the ordinary spectra. Two wavelengths at which the complexes exhibited maximum absorption values for Fe(III) and Al(III) were selected as analytical wavelengths, i.e., 675 and 623.5 nm, respectively. Lambert-Beer's law is obeyed between 0.0896-8.064 microg/mL Fe(III) and 0.054-0.486 microg/mL Al(III). Limits of detection for Fe(III) and Al(III) were 0.056 and 0.044 microg/mL, respectively. The reproducibility, expressed as variation coefficients, for two sets of 10 standard mixtures containing 3.584 microg/mL Fe(III) and 0.27 microg/mL Al(III) were 1.9% and 2% for iron and aluminium, respectively. In the numerical method, a training set was randomly prepared by using 14 samples. The concentration of each component has been varied in the linear range of the analytical signal. The spectral regions between 510 and 720 nm were selected for the analysis of the binary mixture of Fe(III)/Al(III). The proposed methods were validated by using synthetic binary mixtures and applied to the simultaneous determination of Fe(III) and Al(III) in post-haemodialysis samples. The obtained results were compared with each other; in general, both multi-component methods gave rise to similar recovery results for laboratory-prepared mixtures and real samples.