Guidelines for transcutaneous p O2 and p CO2 measurement.

This document provides guidelines in the terminology, methodology, and in the interpretation of data obtained from the use of skin (transcutaneous) p O2 and p CO2 electrodes. The transcutaneous technique has found special application for newborn infants. The causes of analytical bias with respect to arterial blood gas values and imprecision obtained with transcutaneous p O2 and p CO2 electrodes are reviewed. Electrode temperatures above 44 degrees C should not be used routinely, and, at a measuring temperature of 44 degrees C, the measuring site should be changed at least every 4 h to avoid skin burning.     

A study of double tagged two-photon reactions at spear

We have identified 262 doubly tagged two-photon events. A subset of the data shows an enhancement of 21 events in the inclusive two-photon mass squared distribution between 0.8 and 2.2 GeV². If these events result from spin 2 resonance production then Γ_γγ = 9.5 ± 3.9 ± 2.4 keV (statistical and systematic). From another subset of 58 events in which the final state could be classified we determine the two-photon hadron to muon cross section ratio R_γγ = 1.1 ± 0.3 ± 0.3.     

Effect of borohydride reduction on antibodies

The effect of borohydride reducing reagents on monoclonal and polyclonal antibodies was examined by enzyme-linked immunosorbent assay (ELISA). Each antibody showed different stability characteristics to the reducing reagents. Sodium cyanoborohydride was at least five times milder toward immunological activity than sodium borohydride, however, sodium cyanoborohydride with a catalytic amount of metal ion (Zn²⁺ or Al³⁺ ) can be as harsh as sodium borohydride. Activated hydrophobic borohydrides, 9BBN-pyridine, did not have any advantages in respect to the stabilities of antibodies. Antibodies to be used for immunosorbent purification must be evaluated individually to determine whether their structure is stable to immobilization reagents and conditions prior to their linkage to the column support.     

Letters to the Editor

Applied Biochemistry and Biotechnology -     

Laser-induced continuum structure in multiphoton ionisation

Dressed-state resonances can be induced in photoionisation continua by radiative coupling from energetically accessible bound states. Such resonances lead to enhanced photoionisation rates and interference minima. We present results on the effects of saturation and Rabi oscillations on ion yields and asymmetries in AC Stark-split photoelectron spectra.     

Evaluation of gamma-spectrometry equipment for on-site inspection

Journal of Radioanalytical and Nuclear Chemistry - An On-site Inspection (OSI) is an important component of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT),...     

Time sequence determination of parent–daughter radionuclides using gamma-spectrometry

The acquisition of time-stamped list data provides additional information useful to gamma-spectrometry analysis. A novel technique is described that uses non-linear least-squares fitting and the Levenberg–Marquardt algorithm to simultaneously determine parent-daughter atoms from time sequence measurements of only the daughter radionuclide. This has been demonstrated for the radioactive decay of short-lived radon progeny (²¹⁴Pb/²¹⁴Bi, ²¹²Pb/²¹²Bi) described using the Bateman first-order differential equation. The calculated atoms are in excellent agreement with measured atoms, with a difference of 1.3–4.8% for parent atoms and 2.4–10.4% for daughter atoms. Measurements are also reported with reduced uncertainty. The technique has potential to redefine gamma-spectrometry analysis.

     

Supercritical fluid chromatography in research laboratories: design, development and implementation of an efficient generic screening for exploiting this technique in the achiral environment

A new strategy for exploiting SFC in the achiral arena has been designed, developed and successfully implemented in our Analytical Technologies laboratories, in support of Drug Discovery. The development of a generic analytical SFC/MS screening protocol, following extensive evaluation of different stationary phase, modifier and gradient elution combinations, has enabled fast analytical method development for structurally diverse compounds within both specialised and high-throughput purification environments. Application of this approach into the daily routine has provided data on a large number and a wide variety of reaction mixtures. The results confirm the scope and generality of the strategy with more than 85% of targets being successfully resolved from their impurities.     

A strategy for the late-stage divergent syntheses of scyphostatin analogues

This account details the synthesis of two scyphostatin analogues exhibiting a reactive polar epoxycyclohexenone core and various amide side chains outfitted for late-stage chemical derivatization into the desirable lipophilic tails. Our efforts highlight a key ipso-dearomatization process and provide new insights regarding the incompatibility and orthogonal reactivity of scyphostatin's functional groups. We further showcase the utility of resorcinol derived 2,5-cyclohexadienones as synthetic platforms capable of participating in selective chemical reactivity, and we further demonstrate their potential for rapid elaboration into complex structural motifs.