A 29 year-old Nigerian studying in the UK presented with a neck lump and otitis media. Paragonimus-like trematode eggs were found in the neck lump aspirate. Morphologically these eggs resembled Paragonimus uterobilateralis or Achillurbainia congolensis. We favoured the diagnosis of achillurbainiasis over extrapulmonary paragonimiasis on the basis of clinical features and because we could not amplify DNA sequences using PCR primers specific for Paragonimus species. We discuss current diagnostic challenges for this rare parasitic infection.
The ageing of PVC gels made with cyclohexanone has been studied for times up to two weeks by measurement of gel-sol transition temperature and for times up to two years by Raman spectroscopy. The results suggest that the major factor in the ageing of gels of concentration between about 20 and 35% by weight of PVC in cyclohexanone after they are about one day old is that the gels become more homogeneous, with no significant changes in the overall crystallinity or conformational distribution of the PVC taking place. The measurement of gel-sol transition temperature suggests that this process is probably essentially completed within a period of about two weeks but the Raman spectra suggest that there may be some changes in the nature of the PVC-cyclohexanone interaction still taking place for times up to about 150 days and this may be associated with hydrogen bonding.
The paper summarizes some previously reported investigations made into the performance of acoustic hoods for enclosing noisy machinery, and outlines how differing applications require their own particular solution. The importance of having sealed acoustic enclosures is stressed but some of the problems involved with unsealed enclosures are also discussed.
Absorption coefficient and absolute photoionization yield of xenon gas have been measured by photoelectric methods with 0·2Åbandwidth in the 860–1022Åregion. Ionization yields were obtained with a platinum detector calibrated against a calibrated thermocouple. A yield value of unity was obtained throughout this region which includes preionized Rydberg lines. The absorption coefficient at most wavelengths fell between the spread of previous values.
