Quantum statistics of the degenerate four-wave mixing process

A quantum mechanical treatment is given of the degenerate four-wave mixing process. The approximate Heisenberg equation of motion for creation and annihilation operators is solved taking into account attenuation and noise. The solution and the statistics of the modes are discussed both below and above the threshold condition.     

TEMPO/NaIO4-SiO2: a catalytic oxidative rearrangement of tertiary allylic alcohols to beta-substituted alpha,beta-unsaturated ketones

The novel catalytic method for the oxidative rearrangement of tertiary allylic alcohols to beta-substituted alpha,beta-unsaturated ketones is described. TEMPO/NaIO4-SiO2 causes facile and efficient oxidative rearrangement of various acyclic substrates as well as medium-sized and macrocyclic substrates.     

Oxidative rearrangement of tertiary allylic alcohols employing oxoammonium salts

Practical and highly efficient methods for oxidative rearrangement of tertiary allylic alcohols to beta-substituted alpha,beta-unsaturated carbonyl compounds employing oxoammonium salts are described. The methods developed are applicable to acyclic substrates as well as medium membered ring substrates and macrocyclic substrates. The counteranion of the oxoammonium salt plays crucial roles on this oxidative rearrangement.     

Fractional mass filtering as a means to assess circulating metabolites in early human clinical studies

Recent changes in the regulatory environment have led to a need for new methods to assess circulating human drug metabolites in early clinical studies with respect to their potential toxicological impact. The specific goals of such studies are to determine if the metabolites present in human plasma following administration of a drug candidate also are observed in plasma from the animal studies employed for preclinical toxicological evaluation, and to estimate corresponding exposure margins (animal:human) for the major metabolites. Until recently, the accepted best practice for the characterization of circulating drug metabolites utilized liquid chromatography/tandem mass spectrometry (LC/MS/MS)-based methodologies, in conjunction with authentic chemical standards, for the detection and quantitative analyses of metabolites predicted from both animal studies and experiments with human liver preparations in vitro. While this approach is satisfactory for anticipated biotransformation products, metabolites that were not expected to circulate in human plasma frequently escape detection. Current accurate mass instruments enable the use of the technique of fractional mass filtering to detect both expected and unexpected metabolites in a rapid, less resource-intensive and more robust manner. Application of this technology to several clinical development programs at Merck Research Laboratories has demonstrated the value of fractional mass filtering in the assessment of circulating drug metabolites in early clinical trials.     

Nanoparticle plasmon-assisted two-photon polymerization induced by incoherent excitation source

We demonstrate the possibility to achieve optical triggering of photochemical reactions via two-photon absorption using incoherent light sources. This is accomplished by the use of arrays of gold nanoparticles, specially tailored with high precision to obtain high near-field intensity enhancement.