A sialon-containing material based on the Ovruchsk quartzite,aluminum powder,and coke

Conclusions A study of the formation of sialon in a charge based on the Ovruchsk quartzite and fine aluminum powder established that the density of the products increases with increasing content of the aluminum fines in the body (from 40 up to 60%). The material fired at 1450°C in nitrogen atmosphere consists of-sialon, corundum, and a small quantity of aluminum nitride and silicon oxynitride as impurities.Translated from Ogneupory, No. 6, pp. 5–6, June, 1992.     

1-Cyclohexyl-4-(4-arylcyclohexyl)piperazines: Mixed σ and human Δ(8)-Δ(7) sterol isomerase ligands with antiproliferative and P-glycoprotein inhibitory activity

Many new chemotherapeutic agents are under preclinical investigation and, despite efforts to more selectively target cancer cells, limitations such as toxicity and inherent resistance are often encountered. Therefore, alternative strategies are needed to treat cancer and overcome such limitations. We describe novel cyclohexylpiperazine derivatives, designed as mixed affinity ligands for sigma (σ) receptors and human Δ₈–Δ₇ sterol isomerase (HSI) ligands, which also exhibit P‐glycoprotein (P‐gp) inhibitory activity, with the aim of exploiting the antiproliferative effects mediated by σ and HSI sites while overcoming P‐gp‐mediated resistance. All of the compounds displayed high affinities for σ receptors and HSI sites, P‐gp inhibitory activity, and σ₂ receptor agonist antiproliferative activity. Antiproliferative activity was also tested in PC‐3 cells to establish σ₁ and HSI contribution. Compound cis‐ 11 , which displayed the best antiproliferative and P‐gp inhibitory activities, was co‐administered with 0.1 μM doxorubicin in MDCK‐MDR1 cells. Compound cis‐ 11 caused 70 % and 90 % cell death when co‐administered at 30 μM and 50 μm, respectively. When administered alone, cis‐ 11 resulted in 50 % cell death, demonstrating its single agent antitumor properties in a tumor cell line overexpressing P‐gp.     

Dynamics of a reverse osmosis unit with application to pulsating regimes for process optimization

We propose unsteady-state reverse osmosis cell modelling in two dimensions. The convection-diffusion equation describing the concentration of the relevant chemical species is solved by a finite difference technique, while the velocity field is described by empirical expressions for spiral-wound membrane cells. A non-constant permeability is introduced to take into account the effects of membrane compaction at high operating pressures. The role of concentration polarization is discussed for different values of the parameters describing the global process. Finally, the model is applied to predict the effects of a pulsating flow where a cyclic pressure feed is adopted to enhance the permeate flux. In this context, an experimental validation of the model is proposed.