Tunis University

About: Tunis University is a education organization based out in Tunis, Tunisia. It is known for research contribution in the topics: Population & Thin film. The organization has 11745 authors who have published 15400 publications receiving 154900 citations. The organization is also known as: University of Tunis & UT.

A New Equation Relating the Viscosity Arrhenius Temperature and the Activation Energy for Some Newtonian Classical Solvents

Abstract: In transport phenomena, precise knowledge or estimation of fluids properties is necessary, for mass flow and heat transfer computations. Viscosity is one of the important properties which are affected by pressure and temperature. In the present work, based on statistical techniques for nonlinear regression analysis and correlation tests, we propose a novel equation modeling the relationship between the two parameters of viscosity Arrhenius-type equation, such as the energy () and the preexponential factor (). Then, we introduce a third parameter, the Arrhenius temperature (), to enrich the model and the discussion. Empirical validations using 75 data sets of viscosity of pure solvents studied at different temperature ranges are provided from previous works in the literature and give excellent statistical correlations, thus allowing us to rewrite the Arrhenius equation using a single parameter instead of two. In addition, the suggested model is very beneficial for engineering data since it would permit estimating the missing parameter value, if a well-established estimate of the other parameter is readily available.

A bispecific nanobody to provide full protection against lethal scorpion envenoming

Abstract: Envenoming following scorpion sting is a common emergency in many parts of the world Our aim was to ameliorate the current 100-kDa horse plasma antivenom serum (PAS)-derived Fab'(2) to more quickly reach the highly diffusible scorpion toxins (7 kDa) We immunized dromedaries with toxins from Androctonus australis hector (Aah) scorpions and cloned the single-domain antibody fragments or nanobodies (15 kDa) from their B cells Nanobodies against AahI' toxin (with AahII the most toxic compound of the venom) were retrieved from the libraries, and their AahI'-toxin neutralization was monitored in mice Remarkably, the NbAahI'F12 fully protected mice against 100 LD(50) of AahI' administered intracerebroventricularly Moreover, where PAS failed completely to neutralize 2 LD(50) of crude venom injected subcutaneously, the designed bispecific NbF12-10 against AahI'/AahII toxins succeeded in neutralizing 5 LD(50) Finally, in a challenge assay in which mice were subcutaneously injected with a lethal dose of scorpion venom, the subsequent intravenous injection of 85 microg of NbF12-10 protected all mice, even if the whole procedure was repeated 3 times Furthermore, the NbF12-10 remained fully protective when mice with severe signs of envenoming were treated a few minutes before the untreated mice died