Purpose To study the changes in visual and tear film function following superficial excimer laser phototherapeutic keratectomy in patients with mid-stromal corneal scars. Methods Fourteen eyes of 14 patients with mid-stromal corneal scars seen at the Department of Ophthalmology at Kobe Kaisei Hospital underwent superficial phototherapeutic keratectomy (PTK). The subjects underwent routine ophthalmic examinations, corneal sensitivity measurements, tear film break-up time (BUT), Schirmer test and tear film lipid layer interferometry. Thirty eyes of 15 normal control subjects were also studied. The patients and the control subjects were compared for pre-PTK tear function parameters and tear film lipid layer interferometry grade. The alterations in these parameters within 6 months following PTK were also determined. Results Visual improvement was achieved in 12 eyes (86%). A hyperopic shift was observed in all eyes. The average pre-PTK corneal sensitivity and tear film BUT were lower in patients compared with control subjects before PTK. Tear film lipid layer interferometry grades were also higher in the patients than the controls before PTK. All these parameters improved gradually and significantly after PTK. Schirmer test results did not show any significant alterations after PTK. Conclusion We conclude that PTK is an effective means of treating corneal scars and attaining visual improvement, even in cases with deeper corneal involvement, and may obviate the need for corneal transplantation. Simultaneous improvements in corneal sensitivity and tear film stability suggest favourable effects of PTK on the ocular surface.
1'-binaphthalene (Neolephos), which permits the palladium-catalyzed selective carbonylation under mild conditions, providing a general preparation of functionalized 1,3-enynes in good-to-high yields with excellent chemoselectivities. Synthetic applications that showcase the possibilities of this novel methodology include an efficient one-potsynthesis of 4-aryl-4H-pyrans as well as the rapid construction of various
A one-pot synthesis of 1-arylalka-1,3-diynes by sequential acetylene zipper and Sonogashira reactions
作者:Irina A. Balova、Svetlana N. Morozkina、David W. Knight、Sergei F. Vasilevsky
DOI:10.1016/s0040-4039(02)02496-6
日期:2003.1
1,3-Diynes, formed in situ by base-induced acetylene zipper reactions, following anion quenching with water, undergo smooth Sonogashira-type couplings with functionalized aryl iodides, to give good overall yields of 1-arylalka-1,3-diynes.
We developed a technique mediated by visible light for the aerobic homocoupling of terminal alkynes to synthesize 1,3-conjugated diynes using a copper(I) chloride catalyst at room temperature. Compared with previously reported thermal processes, this photochemical method is simple, uses only mild reaction conditions, produces high yields and works well for substrates with electron-withdrawing groups
Aldehyde Addition to 1,3-Butadiyne-Derived Zirconacyclocumulenes: Stereoselective Synthesis of <i>cis</i>-[3]Cumulenols
作者:Xiaoping Fu、Yuanhong Liu、Yuxue Li
DOI:10.1021/om100287d
日期:2010.7.12
1,3-butadiynes is achieved cleanly under controlled reaction conditions, which provids a highly stereoselective method for the synthesis of tetra-substituted [3]cumulenols. DFT calculations suggest that there is an equilibrium between seven-membered zirconacyclocumulene (3) and the less stable but more reactive five-membered α-alkynylzirconaindene (2) in the process. The aldehyde reacts with the five-membered
在受控的反应条件下,可以很干净地将醛直接加到通过苯并锆茂茂与1,3-丁二炔的偶合反应生成的氧化锆环枯烯中,为合成四取代的[3]枯烯醇提供了高度立体选择性的方法。DFT计算表明,在此过程中,七元氧化锆环枯烯(3)与较不稳定但反应性更高的五元α-炔基氧化锆茚(2)之间存在平衡。醛通过环状S E 2'途径与五元氧化锆茚中间体反应,水解后得到枯草烯醇产物。