trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.an efficient epoxidation of β-cf3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and f5-substituted chiral quaternary ammonium salt (1g or 5) derived from...

0. Introduction. Let (A,m) be a regular local ring and let α and β be points of the real spectrum of A centered at m . α and β may be viewed as total orderings on quotients of A . Associated with α and β , there is the so-called “separating ideal”, 〈α, β〉 ⊆ A , which is generated by all a ∈ A such that a is non-negative with respect to α and −a is non-negative with respect to β . 〈α, β〉 is a va...

Carbapenem-hydrolyzing class D β-lactamases (CHDLs) are enzymes of the utmost clinical importance due to their ability to produce resistance to carbapenems, the antibiotics of last resort for the treatment of various life-threatening infections. The vast majority of these enzymes have been identified in Acinetobacter spp., notably in Acinetobacter baumannii. The OXA-2 and OXA-10 enzymes predomi...

The monobactam antibiotic aztreonam is used to treat cystic fibrosis patients with chronic pulmonary infections colonized by Pseudomonas aeruginosa strains expressing CTX-M extended-spectrum β-lactamases. The protonation states of active-site residues that are responsible for hydrolysis have been determined previously for the apo form of a CTX-M β-lactamase but not for a monobactam acyl-enzyme ...

We propose a β-decay experiment based on a sample of ultracold atomic tritium. These initial conditions enable detection of the helium ion in coincidence with the β. We construct a two-dimensional fit incorporating both the shape of the β-spectrum and the direct reconstruction of the neutrino mass peak. We present simulation results of the feasible limits on the neutrino mass achievable in this...

Acinetobacter baumannii isolate AP was recovered from a bronchial lavage of a patient hospitalized in Paris, France. A. baumannii AP was resistant to all β-lactams, including carbapenems, and produced the extended-spectrum β-lactamase (ESBL) GES-14, which differs from GES-1 by two substitutions, Gly170Ser and Gly243Ala. Cloning of the bla(GES-14) gene followed by its expression in Escherichia c...

Gaussian and Chiral β-Ensembles, which generalise well known orthogonal (β = 1), unitary (β = 2), and symplectic (β = 4) ensembles of random Hermitian matrices, are considered. Averages are shown to satisfy duality relations like {β,N, n} ⇔ {4/β, n,N} for all β > 0, where N and n respectively denote the number of eigenvalues and products of characteristic polynomials. At the edge of the spectru...

In this paper we consider the three-dimensional Schrödinger operator with a δ-interaction of strength α > 0 supported on an unbounded surface parametrized by the mapping R2 3 x 7→ (x, βf(x)), where β ∈ [0,∞) and f : R2 → R, f 6≡ 0, is a C2-smooth, compactly supported function. The surface supporting the interaction can be viewed as a local deformation of the plane. It is known that the essentia...