Passive sampling is an approved and accurate method for the assessment of organic compound exposure over long sampling time. This method could be very convenient for the short-time exposure assessment, but passive samplers have to be validated for this use. In this article, the behaviour of two commercial passive samplers (GABIE and Perkin Elmer) under fluctuant concentration conditions is stud...

We evaluated the Perkin-Elmer KA-150 Enzyme Analyzer in a clinical laboratory situation according to a rigid evaluation protocol. The factors evaluated for five commonly assayed enzymes were as follows: (a) rate of analysis of patient samples, (b) analytical linearity, (c) overall precision (within-run and between-day), (d) carry-over from a sample with activity near 1000 U/liter, (e) error det...

In this work we investigate operation in the Geiger mode of the new single photon avalanche photo diode (SPAD) SAP500 manufactured by Laser Components. This SPAD is sensitive in the range 400-1000 nm and has a conventional reach-through structure which ensures good quantum efficiency at the long end of the spectrum. By use of passive and active quenching schemes we investigate detection efficie...

Use of a logic state analyser as a hardware monitoring tool is described. The interrupt handling routines of the UNIX* operating system, running on a Perkin-Elmer 7/32, were measured before and after major code modification. CLock handLing is used as an example. Performance improvements included a reduction in the execution time of the common interrupt handler from 654 to 55 microseconds and a ...

A series of 6-halo-3-hydroxyphenylcoumarins (resveratrol-coumarins hybrid derivatives) was synthesized in good yields by a Perkin reaction followed by hydrolysis. The new compounds were evaluated for their vasorelaxant activity in intact rat aorta rings pre-contracted with phenylephrine (PE), as well as for their inhibitory effects on platelet aggregation induced by thrombin in washed human pla...

The Physiology of Consciousness: PROFESSOR EDChemical Studies on Toad Poisons, IV, Bufagin WIN G. BORING ....................................... 32 and Cinobufagin: DR. H. JENSEN. Cryolysis of Lyophilic Colloids, and its Bearing on the MechaScientific Events: nismn of Enzyme Action: DR. F. P. NORD and 0. M. The Master's Degree for Postgraduate Students in VON RANKE-ABOxYI. Sex Differences in th...

A total of 171 Caucasians living in Andalucia (southern Spain) have been typed for nine short tandem repeat (STR) loci by multiplex PCR amplification using a commercially available kit (Profiler Plus; Perkin-Elmer, Norwalk, CT, USA) and semi-automatic electrophoresis (ABI Prism 377 DNA Sequencer, Applied Biosystems, Foster City, CA, USA). The kit enables typing of the STR loci D3S1358, VWA, FGA...

We wish to express our thanks to Dr Melvin Cohn for much valuable advice during the preliminary work on methods of purification, and one of us (M.R.P.) is greatly indebted to Dr Jacques Monod of the Institut Pasteur, Paris, for the hospitality of his laboratory in which much of the earlier work on isolation ofpenicillinase was carried out. We are also grateful to Dr T. S. Work for help in the c...