27 research outputs found
Structural elucidation of the chlordene isomer constituents of technical chlordane.
The technical chlordane constituents designated α-, β-, and γ-chlordene are isomers of chlordene (C10H6Cl6). These isomers are formed via the rearrangement of chlordene by the action of Cl2 or free-radical initiating agents, and they no longer possess the cyclodiene-type structure. Elucidation of these isomeric structures involved various chemical derivitization reactions. Oxidation with chromic oxide yielded ketones and epoxides while reduction with Zn-HOAc or CrCl2 produced mono- and didechlorinated homologs. Photoisom-ers, in which the two original ClC=CCl bonds had been cross-linked, resulted from their unsensitized uv irradiation. Spectral confirmation of structure was obtained by 1H NMR and gas chromatography-mass spectrometry (GC-MS) studies. It is postulated that α-chlordene is 1,2,3,5,7,8-hexa-chloro-1,3a,4,5,6,6a - hexahydro-1,4-ethenopentalene (III) and β-chlordene is 2,3,3a,4,5,7-hexa-chloro-3a,6,7,7a-tetrahydro-1,6-methano-1H-indene (XIII), with γ-chlordene (XI) being the 2,3,3a,4,5,8-hexachloro isomer of β-chlordene
Farmers and the U.S. Congress: rethinking basic institutional assumptions about agricultural policy
Host and biotic factors affecting sporulation ofstemphylium botryosum f. sp. lycopersici on tomatoes and ofalternaria porri f. sp. sol ani on potatoes
The disappearance and movement of three triazine herhicides and several of their degradation products in soil under field conditions
The purpose and function of humour in health, healthcare and nursing: a literature review
This paper is a report of a review conducted to identify, critically analyse and synthesize the humour literature across a number of fields related to health, health care and nursing. The humour-health hypothesis suggests that there is a positive link between humour and health. Humour has been a focus of much contention and deliberation for centuries, with three theories dominating the field: the superiority or tendentious theory, the incongruity theory and the relief theory. A total of 1630 papers were identified, with 220 fully sourced and 88 included in the final review. There is a dearth of humour research within nursing yet, ironically, an abundance of non-evidence-based opinion citing prerequisites and exclusion zones. Examination of physician-patient interaction and the humour-health hypothesis demonstrates that use of humour by patients is both challenging and revealing, particularly with regard to self-deprecating humour