Transient outflow experiments coupling with an inverse method are promisingto derive soil hydraulic information. The water retention curves obtained from one-step andmulti-step outflow experiments were compared with t...Transient outflow experiments coupling with an inverse method are promisingto derive soil hydraulic information. The water retention curves obtained from one-step andmulti-step outflow experiments were compared with those from the pressure cell method. We found thatin one-step experiments the increment of pressure would reduce the non-uniqueness of inversetechnique and that in multi-step experiment the combination of cumulative outflow with pressure headin the objective function would improve the final estimation and also reduce the non-uniqueness ofinverse problem.展开更多
目的探讨法洛四联症(tetralogy of fallot,TOF)根治术中右心室流出道疏通的最佳直径。方法回顾性分析2011年1月至2016年12月我院心脏外科行TOF根治术的儿童病例308例,2011年1月至2013年12月201例患儿(A组)均采取右心室流出道疏通直径等...目的探讨法洛四联症(tetralogy of fallot,TOF)根治术中右心室流出道疏通的最佳直径。方法回顾性分析2011年1月至2016年12月我院心脏外科行TOF根治术的儿童病例308例,2011年1月至2013年12月201例患儿(A组)均采取右心室流出道疏通直径等同于标准肺动脉瓣环直径;2014年1月至2016年12月107例患儿(B组)采取右心室流出道疏通直径大于标准肺动脉瓣环直径3 mm。所有出院患者术后随访12~36个月。结果A组有17例患者术后出现右心室流出道残余梗阻致低心排血量综合征(low cardiac output syndrome,LCOS),多普勒测右心室流出道流速3.1~4.8(3.8±0.4)m/s,跨肺动脉瓣压差均大于50mmHg,其中6例右心室流出道流速超过4.5m/s,再次手术行右心室流出道疏通术;术后早期死亡5例,随访余12例未发现右心室流出道残余梗阻进一步发展,且均较术后早期明显改善。B组术后无右心室流出道残余梗阻,跨肺动脉瓣压差均小于50mmHg,术后早期死亡2例。随访两组出院患者无三尖瓣、肺动脉瓣大量反流,生长发育良好,心功能均达Ⅰ~Ⅱ级。结论TOF右心室流出道疏通直径等同于标准肺动脉瓣环直径造成术后残余梗阻发生率较高,大于标准肺动脉瓣环直径3mm可有更好的疗效。展开更多
文摘Transient outflow experiments coupling with an inverse method are promisingto derive soil hydraulic information. The water retention curves obtained from one-step andmulti-step outflow experiments were compared with those from the pressure cell method. We found thatin one-step experiments the increment of pressure would reduce the non-uniqueness of inversetechnique and that in multi-step experiment the combination of cumulative outflow with pressure headin the objective function would improve the final estimation and also reduce the non-uniqueness ofinverse problem.
