Nitrogen modified cobalt catalysts supported on carbon were prepared by pyrolysis of the mixture generated from cobalt(II) acetate in aqueous solution of melamine or waste melamine resins, which are widely used as industrial polymers. The obtained nanostructured materials catalyze the transfer hydrogenation of N-heteroarenes with formic acid in the absence of base. The optimal Co/Melamine2@C-70...

A method for the catalytic, enantioselective, intramolecular sulfenoamination of alkenes with aniline nucleophiles has been developed. The method employs a chiral, Lewis basic selenophosphoramide catalyst and a Brønsted acid co-catalyst to promote stereocontrolled C-N and C-S bond formation by activation of an achiral sulfenylating agent. Benzoannulated nitrogen-containing heterocycles such as ...

A highly enantioselective intramolecular Stetter reaction of aromatic and aliphatic aldehydes tethered to different Michael acceptors has been developed. Two triazolium scaffolds have been identified that catalyze the intramolecular Stetter reaction with good reactivity and enantioselectivity. The substrate scope has been examined and found to be broad; both electron-rich and -poor aromatic ald...

Metal selectivity in P1B-type ATPase transporters is determined by conserved amino acid residues in their transmembrane helices responsible for metal binding and transport across the cellular membrane. The Cu(2+)-selective CopB from Archaeoglobus fulgidus has been investigated to explore the coordination chemistry of the transition metal binding sites in P1B-3-type ATPases. Electronic absorptio...

More than one third of all proteins are metalloproteins. They catalyze important reactions such as photosynthesis, nitrogen fixation and CO2 reduction. Metalloproteins such as the olfactory receptors also serve as highly elaborate sensors. Here we review recent developments in functional metalloprotein design using the genetic code expansion approach. We show that, through the site-specific inc...

Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line (6s S0 ↔ 6s6p P1, λ = 791 nm) followed by excitation above the ionization threshold using a nitrogen gas laser (λ = 337 nm). Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation...

A theoretical and experimental study of the effects of variable fiber properties on countercurrent hollow fiber gas separation module performance is presented. Variations in ID, slow gas permeance, and selectivity are considered. Variability in any of these properties is detrimental to performance. The drop in performance increases as either property variation or product purity increase, but pe...

A novel, heterogeneous Pd-MCM-48 catalyst has been developed by encapsulating palladium nanoparticles into the cubic phase of mesoporous MCM-48 matrix at room temperature. The catalyst demonstrated excellent chemo- and regioselectivity for the hydrogenation of olefins at room temperature within 30-80 min. The turnover frequency for the hydrogenation is very high (4400 h(-1)). Interestingly, sel...

AMONGST the numerous derivatives of nitrogen mustard that have been tested for their anti-tumour activity on Walker carcinoma by Danielli and his collaborators (1961), (Cl—CH2—CH2)2: N—C6H4—O—CO—NH—C6H4—COOH, i.e., jp-(AW-Di-2-chloroethyloamino)-phenylAf-(/?-carboxyphenyl) carbamate (later referred to as I.C. 140), has been found to be particularly promising. To check its cytotoxic activity for...

In this study, biodegradable zein protein obtained from maize was used as a novel material to prepare membrane for oxygen/nitrogen separation. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), tensile test, X-ray diffraction (XRD) spectroscopy, differential scanning calorimetry (DSC), biodegradability and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spe...