Videofluoroscopic swallow study training for radiologists-in-training: a survey of practice and training needs.

BACKGROUND: There is a lack of formal, published videofluoroscopic swallow study (VFSS) training targeting radiologists, yet radiology senior medical officers and resident medical officers (i.e., radiologists-in-training, known in Australia as "registrars") are expected to be involved in VFSS interpretation of anatomical anomalies and reporting. This study investigated whether VFSS training is delivered to registrars during their specialist radiology training, whether it is a perceived need and, if so, to determine the desired content for inclusion in a targeted training package. METHODS: A cross-sectional, mixed methods study design was used. An internet-based survey was circulated via convenience and snowball sampling to radiologists (both senior medical officers and registrars) and speech-language pathologists across Australia in October-November 2017. Surveys also were distributed to practitioners based in New Zealand and the United Kingdom, as they practised within similar health systems, and it was anticipated they may have similar VFSS training practices. The radiology survey contained 36 questions and the speech-language pathology survey contained 44 questions. Participants were asked the following: (1) Report their current VFSS radiology registrar training environment; (2) Advise whether radiology registrars need VFSS training; (3) Recommend the content, format, training intensity, and evaluation methods for an effective radiology registrar training package. Demographic data were analysed descriptively, and open-ended responses were analysed using qualitative content analysis. RESULTS: 21 radiology senior medical officers and registrars and 150 speech-language pathologists predominantly based at Australian tertiary hospital settings completed the survey. Most respondents (90.6%) identified that VFSS training is needed for radiology registrars. Only one speech-language pathologist respondent reported that they deliver VFSS training for radiology registrars. Specific content and teaching modalities for a VFSS training package, including diagnosing anatomical anomalies associated with dysphagia were recommended. CONCLUSION: While most of the radiologists and speech-language pathologists surveyed did not deliver VFSS training to radiology registrars, they identified that targeted training is needed to improve radiology registrars' effectiveness and engagement in VFSS clinics. The training package content, format and evaluation methods recommended by participants will inform the development of a VFSS training package targeting radiology registrars to be piloted at an Australian tertiary hospital.

Mechanism of cycloisomerisation of 1,6-heptadienes catalysed by [(tBuCN)2PdCl2]: remarkable influence of exogenous and endogenous 1,6- and 1,5-diene ligands.

The mechanism of the highly regioselective cycloisomerisation of dimethyl hept-1,6-dienyl-4,4-dicarboxylate (1) by a neutral pre-catalyst, [(tBuCN)(2)PdCl(2)] (8), to generate dimethyl 3,4-dimethylcyclopent-2-ene-1,1-dicarboxylate (3) has been investigated by isotopic labelling (reactions involving single and mixed samples of 1,1,2,6,7,7-[(2)H(6)]-1; 3,3,5,5-[(2)H(4)]-1; 1,7-(Z,Z)-[(2)H(2)]-1; [1,3-(13)C(1),5,7-(13)C(1)]-1 and [1,3-(13)C(1),6-(2)H(1)]-1) and by study of the reactions of dimethyl 1-aryl-hept-1,6-dienyl-4,4-dicarboxylates (9 a-e, where aryl is p-C(6)H(4)-X; X=H, OMe, Me, Cl, CF(3)) and dimethyl hept-1,5-dienyl-4,4-dicarboxylate (14), a 1,5-diene isomer of 1. The mechanism proposed involves the generation of a monochloro-bearing palladium hydride which undergoes a simple hydropalladation, carbopalladation, Pd/H dyotropy, beta-H elimination sequence to generate 3. A key point that emerges is that chelation of the 1,6-diene 1 at various stages in the mechanism plays an important role in determining the regioselectivity of the reaction. The selective generation of 3 with pre-catalysts of the form L(2)PdCl(2), as compared to the generation of dimethyl 3-methylene-4-methyl-cyclopentane-1,1-dicarboxylate (2) with pre-catalysts of the form [(MeCN)(2)Pd(allyl)]OTf (5) is ascribed to the absence of chloride ion in the latter, which makes an additional coordination site available throughout turnover. Liberation of the product 3 when [(tBuCN)(2)PdCl(2)] (8) is employed as pre-catalyst, is proposed to proceed via a mono- to bidentate switch in the pi-coordination of diene 1 (eta(2) to bis-eta(2)) displacing pi-coordinated 3 from Pd. When 1-aryl-1,6-dienes 9 are employed as substrates, the electron-donor property of the aryl group is found to influence the regioselectivity of cyclisation. Electron-withdrawing groups favour dimethyl 3-arylmethyl-4-methylcyclopent-2-ene-1,1-dicarboxylates (10), whilst electron-donating aryl groups favour 3-arylidene-4-methyl-cyclopentane-1,1-dicarboxylates (11). The regioselectivity (10/11) correlates with the Hammett sigma(+) values (rho(+)=1.3, r (2)=0.975) indicative of a strong pi-resonance contribution from the aryl ring rather than a simple sigma-inductive effect. Intermolecular modulation of regioselectivity is observed and the net effect proposed to arise through the (pi-->d) donation ability of the vinyl arene in the diene displacing product (10/11) via a mono- to bidentate switch in coordination. The isomerisation process increasingly sequesters Pd as turnover proceeds leading to a powerful inhibition mechanism and ultimately a limitation in turnover number to about 80.