Multidrug resistance (MDR) in cancer is one of the main limitations for chemotherapy success. Numerous mechanisms are behind the MDR phenomenon wherein the overexpression of the ATP-binding cassette (ABC) transporter proteins P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance protein 1 (MRP1) is highlighted as a prime factor. Natural product-derived compounds are being addressed as promising ABC transporter modulators to tackle MDR. Flavonoids and terpenoids have been extensively explored in this field as mono or dual modulators of these efflux pumps. Nitrogen-bearing moieties on these scaffolds were proved to influence the modulation of ABC transporters efflux function. This review highlights the potential of semisynthetic nitrogen-containing flavonoid and terpenoid derivatives as candidates for the design of effective MDR reversers. A brief introduction concerning the major role of efflux pumps in multidrug resistance, the potential of natural product-derived compounds in MDR reversal, namely natural flavonoid and terpenoids, and the effect of the introduction of nitrogen-containing groups are provided. The main modifications that have been performed during last few years to generate flavonoid and terpenoid derivatives, bearing nitrogen moieties, such as aliphatic, aromatic and heterocycle amine, amide, and related functional groups, as well as their P-gp, MRP1 and BCRP inhibitory activities are reviewed and discussed.

The corrosion behavior of nickel (Ni)-based alloys used for low-temperature aqueous or condensed systems is reviewed in detail in this paper. Commercially available pure Ni, nickel-copper (Ni-Cu), nickel-molybdenum (Ni-Mo), nickel-chromium-molybdenum (Ni-Cr-Mo), and nickel-chromium-iron (Ni-Cr-Fe) alloys as well as cast Ni-based alloys are addressed. It is shown that Ni-Cr-Mo alloys are multipurpose alloys that can be used in both reducing and oxidizing conditions. Special attention is given to a few Ni alloys, which not only extend the range of usefulness of existing alloys by overcoming their limitations but are also reliable and cost-effective and have opened new areas of applications.

Three-dimensional (3D) nickel–copper (Ni–Cu) nanostructured foams were prepared by galvanostatic electrodeposition, on stainless steel substrates, using the dynamic hydrogen bubble template. These foams were tested as electrodes for the hydrogen evolution reaction (HER) in 8 M KOH solutions. Polarisation curves were obtained for the Ni–Cu foams and for a solid Ni electrode, in the 25–85 °C temperature range, and the main kinetic parameters were determined. It was observed that the 3D foams have higher catalytic activity than pure Ni. HER activation energies for the Ni–Cu foams were lower (34–36 kJ mol⁻¹) than those calculated for the Ni electrode (62 kJ mol⁻¹). The foams also presented high stability for HER, which makes them potentially attractive cathode materials for application in industrial alkaline electrolysers.