A rapid and sensitive method for the quantification of ganciclovir in plasma using liquid chromatography/selected reaction monitoring/mass spectrometry

A method using reversed-phase liquid chromatography coupled with electrospray ionization and selected reaction monitoring mass spectrometry has been developed for the quantitative analysis of ganciclovir in rat plasma. Acyclovir, a structurally related analog of ganciclovir, was used as the internal standard. A small volume of plasma (50 microL) was spiked with the internal standard and plasma proteins were precipitated by methanol. The supernatant was dried under nitrogen, and then reconstituted in water. The use of liquid chromatography/selected reaction monitoring/mass spectrometry effectively eliminated potential interference from endogenous constituents in the plasma. This highly selective and sensitive method made it possible to analyze plasma ganciclovir with a lower limit of quantitation of 10 ng/mL. The assay was reproducible and linear in the range 10-10,000 ng/mL. The precision and accuracy values were in the range 2.0-6.9% and 89.0-109.6%, respectively. The analyte recovery was greater than 88%. This method was successfully used to monitor the pharmacokinetic profile of ganciclovir in normal rats following intraperitoneal administration of the drug.     

Search for a W' boson via the decay mode W'-->munumu in 1.8 TeV pp collisions

We report the results of a search for a W' boson produced in pp collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W'-->&munumu and search for anomalous production of high transverse mass munumu lepton pairs. We observe no excess of events above background and set limits on the rate of W' boson production and decay relative to standard model W boson production and decay using a fit of the transverse mass distribution observed. If we assume standard model strength couplings of the W' boson to quark and lepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c2 at 95% confidence level.     

A prototype back-action evading transducer suitable for gravitational radiation antennae

This paper describes a practical configuration for a back-action evading motion transducer suitable for use on Weber-type gravitational radiation antennae. Tests on a prototype are described, noise sources are discussed and realistic sensitivity limits are estimated.     

Facial disjunctive programs and sequence of cutting-planes

A cutting-plane procedure for facial disjunctive programs is presented. At each step the point to be cut away and the disjunction used to generate the cut may be chosen freely. Some general comments on finiteness proofs for discrete programs are also given.     

The success of Casson's equation

Summary Many diverse materials, including some which are very unlikely to have a structure such as is postulated byCasson, obey his equation for shear-thinning plastic bodies. When the data range over only one or one and a half decades, as is usual, the curves cannot be visually distinguished from those using theHerschel andBulkley equation for which some explanation, depending much less on any specific type of structure, is already available. It also seems probable that the two equations are indistinguishable if both are transformed to allow for small negative yield-values in dilatant systems.     

Quadrupole spin-flip in elastic scattering of nucleons

We consider the contribution to the depolarization of elastically scattered nucleons which involves transfer of two units of angular momentum to the target nucleus. Our estimates for the depolarization approximate measured values for ⁹Be, ¹⁰B, and ²⁷Al.     

Error bounds for the solution of nonlinear two-point boundary value problems by Galerkin's method

Letu be the solution of the differential equationLu(x)=f(x, u(x)) forx(0,1) (with appropriate boundary conditions), whereL is an elliptic differential operator. Letû be the Galerkin approximation tou with polynomial spline trial functions. We obtain error bounds of the form , where 0jm andmk2m+q,p=2 orp=,h is the mesh size andq is a non negative integer depending on the splines being used.This research was supported in part by the Office of Naval Research under Contract N00014-69-A0200-1017.