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The heme oxygenase/biliverdin reductase (HO/BVR) axis catalyzes the degradation of heme, but this system and its byproducts, carbon monoxide (CO) and bilirubin, have also been shown to exert cytoprotective effects by activating pro-survival pathways and scavenging free radicals. Naturally occurring substances that upregulate the inducible isoform of HO (HO-1) have therefore been proposed as potential new drugs for the treatment of free radical-induced disease. A number of existing drugs have also been shown to regulate the HO/BVR system, and this capacity is considered an additional mechanism for their therapeutic activity. However, upregulation of the HO/BVR axis is not always beneficial for cells: the heme depletion and accumulation of CO and bilirubin it causes are potentially toxic. Therefore, new pharmacological modulators of HO/BVR activity must act in a dose-dependent manner. This would allow dose titration to achieve a desired pharmacologic effect without producing toxicity. Unfortunately, this goal is more complicated than it seems because toxicity has to be defined in terms of each of the main products of heme metabolism. Furthermore, sensitivity to the therapeutic/ toxic effects of these products is likely to be tissue- or cell-type specific. The solution may lie in the use of novel drug-delivery systems that allow targeted delivery of low doses of the HO/BVR modulator to selected tissues.

We analyse the stability of an adaptive cellular network model, similar to a Lotka–Volterra model for population growth. Copyright © 2000 John Wiley & Sons, Ltd.

We study a semi-linear initial-value problem arising from a Boltzmann-like model of vehicular traffic on a motor way supposed infinite and without entrances and exits. We prove the existence and uniqueness of the local (in time) "mild" solution u(t) in L1 and its positivity, if the initial condition u0 = u(0) is positive and belongs to L1 ∪ L∞. Finally, we consider the "mollified" version of the problem, already studied in another paper, and we show that the unique strict solution u6 (t) is such that [image omitted] uniformly in t ε [0,t] with t suitably chosen.

We study a nonlinear initial-value problem arising from a Boltzmann-like model of vehicular traffic on highways. First, we show that such a problem has a unique strict solution u = u(t) that belongs to a suitable Banach space X0, provided that t ε [0,¯] with ¯ suitably chosen. Then, we prove that u(t) belongs to the closed positive cone X+0, if u0 = u(0) belongs to a suitable subset of X+n. Finally, we evaluate a continuous nonnegative real function y(t), such that ‖u(t)‖ ≤ y(t) at any t ε [0, ¯].

Combined static-dynamic compaction of powder material presents advantages for achievement of a higher degree of powder compaction for in dry conditions. One of possible realizations is the use of pulsed electromagnetic compaction (MPC) applied in addition to the static pre-compaction carried out by a hydraulic press. Experimental MPC equipment was used for compaction powders of SiC and Al-B with W fibers at different stages of grinding. The degree of compaction was evaluated by shock plate's displacement at different levels and regimes of dynamic loading. The paper demonstrates feasibility of the method for compaction of the selected ceramic and metal powders and presents some quantitative data for practices.