A proteome-wide protein interaction map for Campylobacter jejuni

'Systematic identification of protein interactions for the bacterium Campylobacter jejuni using high-throughput yeast two-hybrid screens detected interactions for 80% of the organism's proteins

In quest of a systematic framework for unifying and defining nanoscience

This article proposes a systematic framework for unifying and defining nanoscience based on historic first principles and step logic that led to a “central paradigm” (i.e., unifying framework) for traditional elemental/small-molecule chemistry. As such, a Nanomaterials classification roadmap is proposed, which divides all nanomatter into Category I: discrete, well-defined and Category II: statistical, undefined nanoparticles. We consider only Category I, well-defined nanoparticles which are >90% monodisperse as a function of Critical Nanoscale Design Parameters (CNDPs) defined according to: (a) size, (b) shape, (c) surface chemistry, (d) flexibility, and (e) elemental composition. Classified as either hard (H) (i.e., inorganic-based) or soft (S) (i.e., organic-based) categories, these nanoparticles were found to manifest pervasive atom mimicry features that included: (1) a dominance of zero-dimensional (0D) core–shell nanoarchitectures, (2) the ability to self-assemble or chemically bond as discrete, quantized nanounits, and (3) exhibited well-defined nanoscale valencies and stoichiometries reminiscent of atom-based elements. These discrete nanoparticle categories are referred to as hard or soft particle nanoelements. Many examples describing chemical bonding/assembly of these nanoelements have been reported in the literature. We refer to these hard:hard (H-n:H-n), soft:soft (S-n:S-n), or hard:soft (H-n:S-n) nanoelement combinations as nanocompounds. Due to their quantized features, many nanoelement and nanocompound categories are reported to exhibit well-defined nanoperiodic property patterns. These periodic property patterns are dependent on their quantized nanofeatures (CNDPs) and dramatically influence intrinsic physicochemical properties (i.e., melting points, reactivity/self-assembly, sterics, and nanoencapsulation), as well as important functional/performance properties (i.e., magnetic, photonic, electronic, and toxicologic properties). We propose this perspective as a modest first step toward more clearly defining synthetic nanochemistry as well as providing a systematic framework for unifying nanoscience. With further progress, one should anticipate the evolution of future nanoperiodic table(s) suitable for predicting important risk/benefit boundaries in the field of nanoscience

INTRAZEOLITE SEMICONDUCTORS - NA-23 MAS NMR, TL+ LUMINESCENCE QUENCHING, AND FAR-IR STUDIES OF ACID-BASE PRECURSOR CHEMISTRY IN ZEOLITE-Y

Proton-loaded zeolites, prepared from fully dehydrated zeolites and gaseous, anhydrous Bronsted acids, represent an important step in the synthesis of intrazeolite semiconductor quantum supralattices. Adsorption-induced Na-23 MAS NMR chemical shifts, far-IR Na+ and Tl+ translatory mode frequency shifts, and Tl+ luminescence quenching effects were chosen as probes of cation-anion interaction in these materials. Samples of zeolite Y with various loadings of Tl+ were prepared via aqueous ion-exchange techniques. The samples were characterized by powder X-ray diffraction and far-IR spectroscopy. Luminescence measurements revealed Tl+ excitation and emission bands in the UV spectral region. Exposure of thallium Tl(I) zeolite Y to anhydrous HBr quenched the luminescence intensity. The intensity quenching followed Stern-Volmer quenching kinetics. Preliminary luminescence lifetime studies of this system supported a static ion pair quenching model. Compelling additional evidence in favor of cation-anion pair formation comes from the observation of alpha-cage site-specific Na-23 MAS NMR chemical shifts in HBr/Na56Y compared to virgin Na56Y. The relevance of these observations for proton-loaded zeolite Y to the acid-base precursor chemistry involved in the synthesis of semiconductor nanostructures encapsulated in zeolite Y is critically discussed

INTRAZEOLITE METAL-CARBONYL KINETICS - (CO)-C-12 SUBSTITUTION IN MO(12CO)6-NA56Y BY PME3 AND (CO)-C-13

The first kinetic study is reported for archetypical substitution reactions of PMe3 and 13CO with the well defined intrazeolite system, Mo(12CO)6-Na56Y, for which excellent isosbestic points and first order behaviour are obtained, the activation parameters indicate a highly ordered 'supramolecular' transition state consisting of activated Mo(12CO)6 and PMe3 or 13CO all anchored to the Na+ ions in the alpha-cage of the host lattice

INTRAZEOLITE METAL-CARBONYL KINETICS - (CO)-C-12 SUBSTITUTION IN MO(12CO)6-NA56Y BY PME3 AND (CO)-C-13

The first kinetic study is reported for archetypical substitution reactions of PMe3 and 13CO with the well defined intrazeolite system, Mo(12CO)6-Na56Y, for which excellent isosbestic points and first order behaviour are obtained, the activation parameters indicate a highly ordered 'supramolecular' transition state consisting of activated Mo(12CO)6 and PMe3 or 13CO all anchored to the Na+ ions in the alpha-cage of the host lattice.314114