RESUMO
A convenient and broadly applicable method for the hydrohalogenation of ynones is described, by the combination of halotrimethylsilanes and tetrafluoroboric acid. Practically, one equivalent of HX (Brønsted acid) and BF3 (Lewis acid) is smoothly generated, which activates the carbonyl compounds. Through this protocol, 42 examples of (Z)-ß-halovinyl carbonyl compounds (Cl, Br and I) were obtained, in good yields and high stereoselectivity having 2-MeTHF as a solvent.
RESUMO
BACKGROUND: The purpose of the study was to characterize the epidemiological profile and average time on the waiting list of patients undergoing an urgent corneal transplantation (CT) in a referral center in the state of Rio Grande do Norte, northeastern Brazil. METHODS: This cross-sectional study included cases of urgent corneal transplants performed in a referral center from January 2010 to December 2014. Data were collected between January and March 2015. RESULTS: Seventy-four cases of emergency CT were analyzed. Of these, 69.4% were male, over the age range from 8 to 92 years. There were 38 transplants occurring in the right eye, 55.4% with tectonic purpose, 25.7% with optical purpose, and 18.9% therapy purpose. The main indications for patient inclusion in an emergency were the perforation (52.7%) and corneal ulcer unresponsive to medical treatment (33.8%). Interstitial keratitis was the most common diagnosis (74.3%), responsible for all prioritized cases in line for corneal ulcer unresponsive to treatment. The average length of the waiting line to perform the urgent CT was 9.03 days. CONCLUSIONS: In this study, there was a predominance of male patients and patients >50 years old, which corroborates the results of other studies with similar results. Perforation was the main indication to include the patient on the urgency list (52.7%). There is a need for further research to improve public health policies on the process of corneal transplantation as well as raising awareness of the importance of organ donation.
