RESUMO
AIM:To compare the changes of surgically induced corneal higher order aberrations after phacoemulsification with 2.8mm clear corneal incisions at different sites.METHODS:The clinical data of 100 cases (100 eyes) of patients with cataract treated by phacoemulsification with 2.8mm clear corneal incision in our hospital from March 2015 to April 2016 were analyzed retrospectively.According to the site of incision,they were divided into Group A (temporal clear corneal incision,n =55) and Group B (upper clear corneal incision,n=45).Changes of the best corrected visual acuity (BCVA),surgically induced astigmatism (SIA) and corneal topography were compared between the two groups before surgery,at 1d,1wk,1 and 3mo after surgery.The corneal wavefront aberrations were measured by wavefront aberration analyzer,and the changes of higher-order aberrations in corneal 6mm range were recorded.RESULTS:The BCVA of two groups decreased at 1d,1wk,1 and 3mo after surgery (P＜0.05),and the BCVA of Group A at 1d,1wk,and 1mo after surgery was lower than that of Group B (P＜0.05).SIA of the two groups decreased at 1wk,1 and 3mo after surgery (P＜0.05),and the SIA of Group A at different time points after surgery were lower than those of Group B (P＜0.05).The surface asymmetry index (SAI) and the surface rule index (SRI) of the two groups increased at 1 d after surgery,and were gradually decreased at 1wk,1 and 3mo after surgery.The SRI and SAI in Group A were lower than those in Group B at 1d and 1wk after surgery (P＜ 0.05).The total corneal higher-order aberrations (tHOAs) and four-order spherical aberration (SA)showed significant differences between the two groups at 3mo after surgery (P＜0.05).CONCLUSION:The application of 2.8mm temporal clear corneal incision in phacoemulsification can promote the recovery of visual acuity,reduce the effect of surgery on corneal shape,and reduce corneal higher-order aberrations.
RESUMO
A pyridine-catalyzed ylide cyclization affording dihydrofurans and dihydropyrroles has been developed. In the presence of a catalytic amount of pyridine and Fe(Tcpp)Cl, α-ylidene-ß-diketones and α,ß-unsaturated imines react with diazoacetates providing dihydrofurans and dihydropyrroles respectively, in up to 96% yield with high diastereoselectivities.
Assuntos
Furanos/química , Piridinas/química , Pirróis/química , Catálise , Ciclização , Furanos/síntese química , Pirróis/síntese química , EstereoisomerismoRESUMO
On the basis of the reactions of camphor-derived sulfur ylide with alpha,beta-unsaturated ketone, highly efficient and selective synthesis of optically active cyclohexadiene epoxides and vinylcyclopropanes with excellent diastereoselectivities, moderate to high enantioselectivities, and yields has been achieved.
Assuntos
Cicloexenos/síntese química , Ciclopropanos/síntese química , Compostos de Epóxi/síntese química , Compostos de Vinila/síntese química , Ciclização , Cicloexenos/química , Ciclopropanos/química , Compostos de Epóxi/química , Estrutura Molecular , Estereoisomerismo , Compostos de Vinila/químicaRESUMO
Highly diastereoselective synthesis of cis-trisubstituted vinylaziridines containing a quaternary carbon center is realized by a one-pot protocol in which the combination of sulfur ylide-mediated aziridination of cyclic ketimines and Pd(0)-catalyzed isomerization is employed successfully.
Assuntos
Aziridinas/síntese química , Paládio/química , Compostos de Enxofre/química , Compostos de Vinila/síntese química , Aziridinas/química , Catálise , Estrutura Molecular , Estereoisomerismo , Compostos de Vinila/químicaRESUMO
A facile multistep one-pot synthesis of single or fused cyclopentenones has been developed. The sequence involves a transition metal-catalyzed ylide formation/Wittig Olefination/Nazarov Cyclization.
RESUMO
A highly efficient diastereoselective synthesis of cyclohexadiene epoxide derivatives with a multi-stereocenter has been developed via a tandem ylide Michael addition/epoxidation. By employing a chiral sulfonium ylide, up to 96% ee can be achieved in good yields.
