简介:让G一张连接k的图,和T是V(G)的一个子集。如果G-T没被连接,那么,T被说是G的一个切割集合。G的k-cut-setT是有|T的G的一个切割集合|=k。让T是连接k的图G的k-cut-set。如果G-T能被划分成subgraphsG1和G2以便|G1|2,|G2|2,然后,我们把T称为G的重要k-cut-set。假定G是一(k-1)-connected图没有重要(k-1)-cut-set。然后,我们把G称为伪连接k的图。在这份报纸,我们为任何整数k证明那5,如果没有K4,,G是一张连接k的图,那么,G的每个顶点是有其收缩产出伪的一个边的事件连接k的图,因此有至少\(\frac{{|V(G)|}}{2}\)G的边以便他们的每个成员的收缩导致伪连接k的图。
简介:AIM:Toinvestigatetheefficacyandsafetyofkryptonlaserperipheraliridoplasty(LPIP)forChinesepatientswithprimaryangleclosure(PAC)orprimaryangle-closureglaucoma(PACG)statuspostlaseriridotomyinreversingthepositiveresultsofthedarkroomprovocativetest(DRPT).METHODS:Thisstudywasprospective,noncomparative,interventionalcaseseries.Thirty-threepatients(thirty-eighteyes)withPACorPACGstatuspostpatentlaseriridotomyandmaintainednormalintraocularpressure(IOP)butwithpositiveDRPTresultswereenrolled.AllthesubjectsweretreatedwithkryptonLPIP.DRPTwasrepeatedafterkryptonLPIP.ResultsofDRPTwererecorded.Thevisualacuity,IOPandgonioscopywereanalyzedbeforeandafterkryptonLPIP.Aminimumtimelimitforfollow-upwas6mo.RESULTS:Thirty-threepatients(thirty-eighteyes)werefollowedfor17.7±8.37mo(range7-41mo)afterLPIP.PositiveresultsofDRPTdecreasedfrom38eyesto9eyes(23.7%)afterLPIP.Peripheralanteriorsynechiaeofanglein34of38eyes(89.5%)remainedunchangedatdynamicgonioscopythroughoutthefollow-upperiodafterLPIP.CONCLUSION:LPIPdecreasedpositiveratesoftheDRPTsignificantly.ThemechanismmaybethatLPIPminimizedcontactbetweentheperipheralirisandtrabecularmeshwork,whichisakeyfactorfordevelopingperipheralanteriorsynechiae.