Modification of Tefzel film through graft copolymerization

The graft copolymerization of styrene (st) and methacrylonitrile (MAN) onto Tefzel film in aqueous media by the preirradiation method has been studied. In order to follow the effect of preswelling of the backbone polymer, grafting was attempted onto preirradiated Tefzel film and monomer preswollen, preirradiated Tefzel film. Optimum conditions pertaining to maximum percentage of grafting of st and MAN have been evaluated. Grafting onto preswollen, preirradiated Tefzel film displayed better results. The effect of different alcohols of increasing chain length on the percentage of grafting of st and MAN was also studied. Graft copolymerization of st showed an increase, while grafting with MAN exhibited a decrease, in the percentage of grafting in the presence of alcohols as compared to that obtained in the aqueous medium. Characterization of the graft copolymers was made by IR and thermogravimetric studies. Tefzel‐graft‐polystyrene showed improved thermal stability while the MAN grafted onto preswollen, preirradiated Tefzel film produced graft copolymer with poor thermal stability. Copyright © 2004 Society of Chemical Industry     

Post-tonsillectomy bacteraemia in children

It has been postulated that the bacteraemia rate following guillotine tonsillectomy is lower than that following dissection tonsillectomy due to intra-operative compression of tonsillar blood vessels by the guillotine. The aim of this study was to evaluate the incidence of bacteraemia following dissection and guillotine tonsillectomy. Sixty-four patients undergoing elective tonsillectomy for recurrent acute tonsillitis were randomly selected, 32 underwent dissection tonsillectomy and 32 guillotine tonsillectomy. Positive intra-operative blood cultures were obtained in 16 patients (25 per cent), nine (28.1 per cent) of the dissection group and seven (21.8 per cent) of the guillotine group. There was no significant difference between the two methods (Chi-squared test, p = 0.77).     

Men and women in optometry. II. Attitudes toward career and family

BACKGROUND: Optometry has experienced a dramatic upward shift in the percentage of women entering the profession during the past 20 years. Our survey assessed the mechanisms for sustaining balance in professional and personal roles used by women optometrists and how these mechanisms may differ from those of their male colleagues. METHODS: A survey questionnaire was mailed to a large nationwide random sample of optometrists, composed of equal numbers of men and women. RESULTS: Data were analyzed from 353 men and 358 women; margin of error was +4%. Most of the respondents indicated they derived personal satisfaction from their career. A majority of both groups did not indicate that lack of time for their career was a source of frustration. However, significantly more women than men indicated some frustration in pursuing those activities that lead to career advancement. There were significant differences in response patterns of men and women about the effect of family, child care, and household work on their careers. CONCLUSIONS: Both men and women optometrists are satisfied with their careers and neither group feels compelled to choose between career and family. Optometrists do not fit into one pattern, but instead make individualized career choices on the basis of needs.     

Aggregation attractant of the European elm bark beetle,Scolytus multistriatus

The three components of theScolytus Multistriatus aggregation attractant-4-methyl-3-heptanol (1), -multistriatin (2), and -cubebene (3)-were collected from beetles and elm wood by aeration, solvent extraction of host tissue, or solvent extraction of beetles and beetle parts. Bioassays and analysis of extracts demonstrated that (a) compounds 1 and 2 are produced by virgin females and 3 is host-produced, (b) cessation of the production of 1 is coincident with diminished attractiveness of females after they have been joined by males, (c) the release of 3 from elm wood is augmented by attacking beetles, and (d) the level of 3 is related to the condition of the wood, and fungal growth (particularlyceratocystis ulmi) may lead to increased levels of 3. Compound 1 was concentrated in the upper abdominal area and 2 in the abdomen tips, but neither component was in the hindgut. A gland opening through the vaginal palpi (a pair of sclerotized conical structures) was circumstantially associated with the release of 2. Compounds 1, 2, and 3 are regulatory agents that contribute to the initiation and maintenance of the beetle-elm-microorganism biosystem.Coleoptera:Scolytidae.