A cascade electro-dehydration process for simultaneous extraction and enrichment of uranium from simulated seawater.

Uranium extraction from seawater has become a crucial issue that has raised tremendous attention. The transport of water molecules along with salt ions through an ion-exchange membrane is a common phenomenon for typical electro-membrane processes such as selective electrodialysis (SED). In this study, a cascade electro-dehydration process was proposed for the simultaneous extraction and enrichment of uranium from simulated seawater by taking advantage of water transport through ion-exchange membranes and the high permselectivity of membranes for monovalent ions against uranate ions. The results indicated that the electro-dehydration effect in SED allowed 1.8 times the concentration of uranium with a loose structure CJMC-5 cation-exchange membrane at a current density of 4 mA/cm2. Thereafter, a cascade electro-dehydration by a combination of SED with conventional electrodialysis (CED) enabled approximately 7.5 times uranium concentration with the extraction yield rate reaching over 80% and simultaneously desalting the majority of salts. Overall, a cascade electro-dehydration is a viable approach, creating a novel route for highly effective uranium extraction and enrichment from seawater.

Pharmaceutical applications of dendrimers: promising nanocarriers for drug delivery.

Dendrimers are new artificial macromolecules which have the structure like a tree. They are hyperbranched and monodisperse three-dimensional molecules with defined molecular weights, large numbers of functional groups on the surface and well-established host-guest entrapment properties. Recently, dendrimers have successfully proved themselves as promising nanocarriers for drug delivery because they can render drug molecules a greater water-solubility, bioavailability, and biocompatibility. In this review, recent progress in the pharmaceutical applications of dendrimers as delivery systems for drugs, particularly, the non-steroidal anti-inflammatory, anti-microbial/anti-viral and potent anti-cancer drugs is discussed. Three possible interaction mechanisms between dendrimers and drug molecules are presented. In addition, the pharmacodynamic and pharmacokinetic properties of both dendrimer/drug complex and dendrimer-drug conjugation after their administration to animals are evaluated.

Elemental selenium at nano size (Nano-Se) as a potential chemopreventive agent with reduced risk of selenium toxicity: comparison with se-methylselenocysteine in mice.

Selenium (Se) is an essential trace element with a narrow margin between beneficial and toxic effects. As a promising chemopreventive agent, its use requires consumption over the long term, so the toxicity of Se is always a crucial concern. Based on clinical findings and recent studies in selenoprotein gene-modified mice, it is likely that the antioxidant function of one or more selenoproteins is responsible for the chemopreventive effect of Se. Furthermore, upregulation of phase 2 enzymes by Se has been implicated as a possible chemopreventive mechanism at supranutritional dietary levels. Se-methylselenocysteine (SeMSC), a naturally occurring organic Se product, is considered as one of the most effective chemopreventive selenocompounds. The present study revealed that, as compared with SeMSC, elemental Se at nano size (Nano-Se) possessed equal efficacy in increasing the activities of glutathione peroxidase, thioredoxin reductase, and glutathione S-transferase, but had much lower toxicity as indicated by median lethal dose, acute liver injury, survival rate, and short-term toxicity. Our results suggest that Nano-Se can serve as a potential chemopreventive agent with reduced risk of Se toxicity.