RESUMO
Allylic azlactones are greatly significant in terms of potential bioactivities and synthetic applications. Owing to the burgeoning interest of the pharmaceutical industry in α-amino acid derivatives, discovering strategies for the synthesis of allylic azlactones is important. Herein, we establish a transition-metal-free regioselectivity switch of α-amino acid-derived esters and MBH carbonates, which exhibits broad reaction scope and good reaction yields. Control reactions indicate that both base and solvent are important for regioselectivity.
RESUMO
The current situation of the CO2 laser treatment apparatus in hospital was evaluated through actual investigation and testing data in this paper. The existing problems have been analyzed and the solutions are proposed, which wil play a role in maintenance, testing and drafting standards for this kind of medical devices being used in hospital.
Assuntos
Terapia a Laser/instrumentação , Lasers de Gás , Padrões de ReferênciaRESUMO
Grounding impedance measurement is a traditional proficiency testing programs, 2014 proficiency testing program on the basis of original ability to verify, combined with actual detection need, innovation introduced two verification point of the power input socket and metal plane testing. This paper analyzes and discusses the results of the ability verification in 2014, and puts forward the points of attention and the recommended method of metal plane test.