Electronic computation of first-order wave functions using green's functions

Green's functions and the symbol manipulative computer language LISP have been used to obtain exact, closed form, first-order functions and second-order energies for the first fourteen states of the hydrogen atom in electric and magnetic fields.     

Stereospecific biocatalytic epoxidation: the first example of direct regeneration of a FAD-dependent monooxygenase for catalysis

Catalysis for chemical synthesis by cell-free monooxygenases necessitates an efficient and robust in situ regeneration system to supply the enzyme with reducing equivalents. We report on a novel approach to directly regenerate flavin-dependent monooxygenases. The organometallic complex [CpRh(bpy)(H(2)O)](2+) catalyzes the transhydrogenation reaction between formate and isoalloxazine-based cofactors such as FAD and FMN. Coupling this FADH(2) regeneration reaction to the FADH(2)-dependent styrene monooxygenase (StyA) resulted in a chemoenzymatic epoxidation reaction where the organometallic compound substitutes for the native reductase (StyB), the nicotinamide coenzyme (NAD), and an artificial NADH regeneration system such as formate dehydrogenase. Various styrene derivatives were converted into the essentially optically pure (S)-epoxides (ee > 98%). In addition, StyA was shown to be capable of performing sulfoxidation reactions. The productivity of the chemoenzymatic epoxidation reaction using 6.5 microM StyA reached up to 6.4 mM/h, corresponding to approximately 70% of a comparable fully enzymatic reaction using StyB, NADH, and formate dehydrogenase for regeneration. The coupling efficiency of the nonenzymatic regeneration reaction to enzymatic epoxidation was examined in detail, leading to an optimized reaction setup with minimized quenching of the electron supply for the epoxidation reaction. Thus, up to 60% of the reducing equivalents provided via [CpRh(bpy)(H(2)O)](2+) could be channeled into epoxide rather than hydrogen peroxide formation, allowing selective synthesis with high yields.     

A minor groove binding copper-phenanthroline conjugate produces direct strand breaks via beta-elimination of 2-deoxyribonolactone

Copper-phenanthroline complexes and their conjugates are useful reagents for studying nucleic acid interactions. Although DNA cleavage by such complexes was discovered more than 20 years ago, significant questions remain unanswered regarding the chemical mechanism(s) by which DNA is damaged. Kinetic evidence is provided, which demonstrates that the major pathway for DNA damage by a minor groove binding molecule conjugated to copper phenanthroline (6) involves C1'-oxidation. Additional experiments using 6 and a DNA substrate containing 2-deoxyribonolactone (1) show that direct strand breaks are produced via beta-elimination from 1. These studies support the original mechanism for DNA damage by copper phenanthroline put forth by Sigman and a more recent proposal concerning the mechanism for direct strand break formation.     

Synthesis of 2‐amino‐1,4‐dihydro‐4‐quinolinones and diaminomethylene meldrum's acids derivatives as potential potassium channel openers

Starting from 5‐bismethylthiomethylene Meldrum's acid, the synthesis of 5‐diaminomethylene Meldrum's acids and 2‐aminoquinolone derivatives, structurally related to potassium channels openers pinacidil and diazoxide, is described.     

Methylidyne tricobalt nonacarbonyl clusters; optically active silicon and germanium derivatives,and substitutions at silicon

The preparation and alcoholysis of chiral chlorosilanes containing the nonacarbonyltricobaltcarbon cluster, RR′Si(Cl)CCo₃(CO)₉, is described. The alkoxy derivatives react with i-Bu₂AlH or BF₃ · Et₂O to give the corresponding silicon hydride or fluoride. Reaction of methylidynetricobalt nonacarbonyl with optically active silanes of germane gave the optically active cluster complexes R¹R²R³M^*CCo₃(CO)₉ (M^* = Si, Ge). These compounds react with phosphine to give the monosubstituted R¹R²R³M^*CCo₃(CO)₈(PR₃ (M^* = Si, Ge). The diastereomers have been resolved in the case of the MePhSi (Obornyl) CCo₃(CO)₉ complex.     

The double-wedge algebra for quantum fields on Schwarzschild and Minkowski spacetimes

We consider the Klein-Gordon equation (m0) on the double Schwarzschild wedge of the Kruskal spacetime, and construct the Hartle-Hawking state _H as a thermal state relative to the Boulware quantization. We prove that, on the double wedge, _H is a pure state, and in the corresponding representation, the left- and right-wedgeC* algebras each have the Reeh-Schlieder property, while the corresponding von-Neumann algebras are typeIII ₁ factors which are dual to (i.e. commutants of) each other. We discuss the extent to which these properties may generalize to non-quasi-free field theories.Pursuing the Rindler-Fulling-Unruh analogy with the Klein-Gordon equation (m>0) in (d-dimensional) flat spacetime, we establish an explicit formula for the Minkowski vacuum on a spacelike double wedge as a thermal state relative to the Fulling quantization. We also treat the cased=2,m=0 of this formula since this is essential input for a paper with Dimock on scattering theory for the quantum Klein-Gordon equation on the Schwarzschild metric.Research supported in part by the Schweizerischer Nationalfonds     

Application of microchip assay system for the measurement of C-reactive protein in human saliva

In the last decade, saliva has been advocated as a non-invasive alternative to blood as a diagnostic fluid. However, use of saliva has been hindered by the inadequate sensitivity of current methods to detect the lower salivary concentrations of many constituents compared to serum. Furthermore, developments in the areas related to lab-on-a-chip systems for saliva-based point of care diagnostics are complicated by the high viscosity and heterogeneous properties associated with this diagnostic fluid. The biomarker C-reactive protein (CRP) is an acute phase reactant and a well-accepted indicator of inflammation. Numerous clinical studies have established elevated serum CRP as a strong, independent risk factor for the development of cardiovascular disease (CVD). CVD has also been associated with oral infections (i.e. periodontal diseases) and there is evidence that systemic CRP may be a link between the two. Clinical measurements of CRP in serum are currently performed with "high sensitivity" CRP (hsCRP) enzyme-linked immunosorbent assay (ELISA) tests that lack the sensitivity for the detection of this important biomarker in saliva. Because measurement of salivary CRP may represent a novel approach for diagnosing and monitoring chronic inflammatory disease, including CVD and periodontal diseases, the objective of this study was to apply an ultra-sensitive microchip assay system for the measurement of CRP in human saliva. Here, we describe this novel lab-on-a-chip system in its first application for the measurement of CRP in saliva and demonstrate its advantages over the traditional ELISA method. The increased sensitivity of the microchip system (10 pg ml(-1) of CRP with 1000-fold dilution of saliva sample) is attributed to its inherent increased signal to noise ratio, resulting from the higher bead surface area available for antigen/antibody interactions and the high stringency washes associated with this approach. Finally, the microchip assay system was utilized in this study to provide direct experimental evidence that chronic periodontal disease may be associated with higher levels of salivary CRP.     

The Near-Infrared (3)Phi --> (1)(3)Delta Transition of LaF

Rotational analyses of 32 subbands of the near-infrared (3)Phi --> (1)(3)Delta system of LaF have been carried out, involving the levels v = 0-7 of the two states. The three subsystems were first treated as separate singlet systems, directly at equilibrium. Perturbations were revealed in the lower state, ascribed to spin-uncoupling interactions between (1)(3)Delta(3)(v) and (1)(3)Delta(2)(v + 1) levels. A 21 x 21 matrix representation at equilibrium of the complex of interacting levels (v = 0-6) was then constructed, each diagonal v-block corresponding to a triplet model of the rovibrational (3)Delta Hamiltonian. The observed perturbations were completely reduced in the harmonic oscillator approximation with an experimental value of the interaction parameter B(Delta)(0,1) = 0.01322(2) cm(-1). The wavenumbers of some 4500 lines of the system were fitted with an rms error of about 0.005 cm(-1). (Line lists are available in electronic form via http://www-obs.univ-lyon1.fr/~ABernard/index.html.) Copyright 2000 Academic Press.