Glyconanoparticle-DNA interactions: an atomic force microscopy study.

Glyconanoparticles which present carbohydrate and amino groups motifs at their surface were produced. These particles were highly stable and soluble in aqueous solutions. The presence of the carbohydrate groups also allowed the inclusion of more strongly binding groups, without affecting solubility. The binding of a model DNA, plasmid by these nanoparticles was studied by atomic force microscopy, transmission electron microscopy, and gel electrophoresis. Significant differences between the nanoparticles based on their affinities for the DNA were found, with implications for their potential use as nonviral gene delivery agents.     

Nanoweb Formation: 2D Self‐Assembly of Semiconductor Gallium Oxide Nanowires/Nanotubes

This paper reports a method to produce networks of crystalline gallium oxide comprised of one‐dimensional (1D) nanostructures. Because of the unique arrangement of wires, these crystalline networks are termed as ‘nanowebs’. Nanowebs are of great technological interest since they contain wire densities of the order of 10⁹ cm^–2. A possible mechanism for the fast self‐assembly of crystalline metal oxide nanowires involves multiple nucleation and coalescence via oxidation–reduction reactions at the molecular level. The preferential growth of nanowires parallel to the substrate enabled them to coalesce into regular polygonal networks. The individual segments of the polygonal network consist of both nanowires and nanotubules of β‐gallium oxide. Individual wire properties contribute to a nanoweb’s overall capacity and the implications for devices based on nanowebs are expected to be enormous.     

Active transport of nitrofurantoin across the mammary epithelium in vivo

Nitrofurantoin is a commonly used urinary tract antibiotic that has been found at high concentrations in human milk. In vivo studies in rats were carried out to determine the mechanism by which this drug crosses the mammary epithelium. Lactating rats were gavage-fed with nitrofurantoin, and their milk and plasma levels of the antibiotic were measured at intervals up to 8 hr. The average milk-to-plasma (M/P) ratio, calculated from the areas under the milk and plasma curves, respectively, was 23 compared with a ratio predicted to be about 0.3 on the basis of lipid partitioning and protein binding determinations. M/P ratios for two nitrofurantoin congeners were also calculated. The neutral compound furazolidone had a M/P ratio of about 1, as predicted, whereas the basic compound furaltadone had a M/P ratio of 3.49 compared with a predicted ratio of 1.4. These data suggest that nitrofurantoin and, to a lesser extent, furaltadone are actively transported across the mammary epithelium into milk.     

Indexing transitional knowledge.

Various indexes have been proposed to mark when a child is on the verge of acquiring new knowledge. This article described a new method for indexing this point of transition, which is based on the specificity of children's verbal explanations. The degree to which children were specific in their verbal explanations was related to whether they benefited from instruction. In particular, children who were vague in their explanations (i.e., less specific) benefited from instruction more than children who were explicit in their explanations (i.e., more specific). This index provides insights into the child's mental state prior to acquiring new knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)