ABSTRACT Introduction: To assess the effect of a hands-on ultrasound training session to teach urologic trainees ultrasound-guided percutaneous needle placement. Materials and methods: University of California, San Francisco (UCSF) urology residents completed a time trial, placing a needle into a phantom model target under ultrasound guidance. Participants were randomized into three educational exposure groups: Group 1's time trial occurred prior to any teaching intervention, group 2's after experiencing a hands-on training module, and group 3's after exposure to both the training module and one-on-one attending feedback. Needle placement speed and accuracy as well as trainees' perceived confidence in utilizing ultrasound were measured. Results: The study cohort consisted of 15 resident trainees. Seven were randomized to group 1, three to group 2, and five to group 3. All residents reported minimal prior ultrasound experience. Their confidence in using ultrasound improved significantly after completing the training module with the most significant improvement seen among junior residents. Time to needle placement was fastest after receiving attending feedback (46.6sec in group 3 vs. 82.7sec in groups 1 and 2, p<0.01). Accuracy also improved with attending feedback, though the number of repositioning attempts did not differ significantly between groups. Conclusions: A hands-on training module and use of an abdominal phantom trainer increased resident confidence and skill in their use of ultrasound to guide percutaneous needle positioning. Attending feedback is critical for improving accuracy in needle guidance toward a target. Ultrasound-guided needle positioning is a teachable skill and can be applicable to multiple urologic procedures.

Um método de membrana líquida (BLM) usando O, O'-dibenzoil-(2S, 3S)-ácido tartárico foi desenvolvido para o transporte enantioseletivo do clenbuterol racêmico. A influência do pH tampão e da relação entre as concentrações do veículo quiral e do clenbuterol racêmico foi estudada. Verificou-se que as escolhas de pH 7 em solução aquosa e a relação entre as concentrações de 1:4 foram apropriadas. O modelo de transporte cinético estabelecido envolveu duas reações consecutivas irreversíveis de primeira ordem e foram determinadas as constantes de reação aparente de pseudo-primeira ordem. Esse modelo foi adequado para a otimização dos sistemas BLM de transporte visando à produção em larga escala do enantiômero puro.

A method of bulk liquid membrane (BLM) using O, O'-dibenzoyl-(2S, 3S)-tartaric acid was developed for the enantioselective transport of racemic clenbuterol. The influence of buffer pH, concentration ratio of chiral carrier to clenbuterol were studied. It was an appropriate choice of such as pH 7 in aqueous solution and concentration ratio of 1:4. The model of kinetic transport was established by means of a kinetic model involving two consecutive irreversible first order reactions. The pseudo-first order apparent rate constants were determined. It is helpful for optimizing the transport of BLM systems and realizing the large-scale production of pure enantiomer.