Synthesis and intramolecular charge-transfer interaction of o-tropyliobiphenyl tetrafluoroborates

A series of o-tropyliobiphenyl tetradfluoroborates

has been synthesized. Evidences are presented to show that

exhibit strong intramolecular charge-transfer interaction between tropylium ion and remote aryl ring. The structure of

was determined by single crystal X-ray diffraction study.     

In vitro monitoring of GTPase activity and enzyme kinetics studies using capillary electrophoresis

A capillary electrophoresis (CE)-based method for the in vitro detection and monitoring of nucleotide-triphosphatase activity is described. This robust and reproducible method was used to investigate GTPase activity of a recombinant protein construct containing the catalytic domain of Human SEPT4/Bradeion β (GST-rDGTPase). This example application demonstrates that the CE technique can replace classical radioactive methods for GTPase activity assays and may be used as a routine analytical tool. Enzyme kinetics of GST-rDGTPase was studied and yielded the following kinetic parameters: v _max = 1.7 μM min⁻¹ ± 0.1, Km = 1.0 mM ± 0.3, and apKcat = 9 × 10⁻³ s⁻¹. In addition the effect of co-factors such as Mg²⁺ and Mn²⁺ on the catalytic activity was investigated. The described analytical method was also shown to be useful to analyze diphosphated and triphosphated forms of other nucleotides.     

Mycobacterium tuberculosis H37Rv3377c encodes the diterpene cyclase for producing the halimane skeleton

The cloning and functional expression of Mycobacterium tuberculosis Rv3377c in Escherichia coli revealed that this gene encodes the diterpene cyclase for producing (+)-5(6),13-halimadiene-15-ol, which accepts geranylgeranyldiphosphate as the intrinsic substrate.     

聚合物／石墨复合材料电极及其在银离子测定中的应用

用石墨粉填充苯乙烯－丙烯腈共聚树脂（ＡＳ树脂），挤出成型，制取ＡＳ树脂／石墨复合导电材料电极．用红外光谱、循环伏安等手段表征了电极的结构及特性．电极对测定Ａｇ＋有较好的选择性、稳定性和再现性，并较一般玻碳电极更易化学修饰     

Ni2P Nanoalloy as an Air-Stable and Versatile Hydrogenation Catalyst in Water: P-Alloying Strategy for Designing Smart Catalysts

Non-noble metal-based hydrogenation catalysts have limited practical applications because they exhibit low activity, require harsh reaction conditions, and are unstable in air. To overcome these limitations, herein we propose the alloying of non-noble metal nanoparticles with phosphorus as a promising strategy for developing smart catalysts that exhibit both excellent activity and air stability. We synthesized a novel nickel phosphide nanoalloy (nano-Ni₂P) with coordinatively unsaturated Ni active sites. Unlike conventional air-unstable non-noble metal catalysts, nano-Ni₂P retained its metallic nature in air, and exhibited a high activity for the hydrogenation of various substrates with polar functional groups, such as aldehydes, ketones, nitriles, and nitroarenes to the desired products in excellent yields in water. Furthermore, the used nano-Ni₂P catalyst was easy to handle in air and could be reused without pretreatment, providing a simple and clean catalyst system for general hydrogenation reactions.     

Laser speckle analysis on correlation between gelation and phase separation in aqueous methyl cellulose solutions

Structure formation by coupling between formation of crosslinking points and liquid–liquid phase separation was investigated for aqueous methyl cellulose solution by small‐angle X‐ray scattering (SAXS) and light scattering (LS) techniques. The sol–gel phase diagram and the SAXS results suggested that the liquid–liquid phase separation occurred before gelation. By LS measurements, the structure due to the liquid–liquid phase separation was directly observed. By applying speckle analysis on the LS profiles, it was suggested that the gelation and the phase separation strongly coupled each other: the increase in the apparent molecular weight by crosslinking induced the liquid–liquid phase separation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 168–174, 2010