RESUMO
Polyacrylonitrile (PAN) fabrics meet the customers' requirements in many aspects. Nevertheless, PAN fabrics suffer from low moisture regain and the accumulation of electrostatic charges on the fabric surface. Some PAN products exhibit rough a surface which is uncomfortable for human skin. Herein, we synthesized a new hydrophilic nonionic softener by reacting a fatty acid (FA), extracted from wool wax, with 2-amino-2-methyl-1,3-propanediol (AMPD). Adopting the pad-dry-cure technique, the synthesized softener was chemically bound to pretreated PAN fabrics. Without deterioration of the fabrics' mechanical properties, new functions have been imparted to the treated PAN fabrics, viz., silk-like hand, induced resistance to the accumulation of electrostatic charges, and improved wettability. Fourier-transform infrared (FTIR) spectroscopy and carbon-13 nuclear magnetic resonance (13C-NMR) were utilized for the structure elucidation of the prepared softener as well as to determine whether AMPD reacts with the fatty acid through its amino or hydroxyl group. The mechanism of the preparation of the softener as well as its mode of action on PAN fabrics were proposed. The effects of the applied softener on air and water permeability, ultraviolet protection factor (UPF), stiffness, tensile properties, and yellowness of the treated fabric were studied. The scanning electron micrographs of the treated fabric revealed the existence of a layer of the applied softener on the fabric surface. The finished fabric was found to be durable against washing for up to 20 cycles in terms of the fabric smoothness and durability.
RESUMO
An 18-20 kDa Cryptosporidum coproantigen (18-20 CCA), had been detected in the stool of infected humans and calves. A purified, electroeluted and concentrated 18-20 kDa antigen was tested in Ussing chamber, and electric parameters were tested before and after the addition of this antigen. A significant increase in the short circuit current (Isc) was detected. The enterotoxic effectof 18-20 kDa CCA, was time and dose dependent, heat labile, and Cl- dependent. The detected change in the short circuit current was not detected when the 18-20 kDa antigen wa incubated with its monospecific antibodies. These results indicate an enterotoxic activity of the 18-20 kDa antigen secreted from the released parasite and detected in stool of infected humans and calves. Additionally, they may help in developing an appropriate anti-secretory therapy for the intractable diarrhoea caused by cryptosporidiosis.