超声检查在新生儿胎粪性腹膜炎诊断中的价值

目的:探讨超声在新生儿胎粪性腹膜炎(MP)中的诊断价值,总结MP的超声特点。方法:回顾性搜集2017年1月-2021年12月在本院经临床诊断或手术病理证实的78例胎粪性腹膜炎患儿的病例资料。结合临床资料、术中所见及病理诊断,分析和总结MP的术前超声特征以及未确诊的原因,并通过与腹部平片及其结合CT或消化道造影(放射学联合检查)的诊断结果进行比较,明确超声检查对MP的诊断价值。结果:78例中63例超声诊断为MP,诊断符合率为80.8%,腹部平片的诊断符合率为42.3%,腹部平片结合CT或消化道造影检查的诊断符合率71.8%,三种方法诊断符合率的差异有统计学意义(χ^(2)=27.7,P<0.05)。78例的超声表现主要包括腹腔钙化灶53例,肠梗阻38例,肠粘连31例,同时伴肠粘连及肠梗阻28例,腹腔假性囊肿30例,腹腔积液21例,腹腔游离积气10例。超声未确诊的15例中3例因气体干扰严重仅诊断为腹腔胀气,2例仅诊断为腹腔积液,6例诊断为单纯肠梗阻,2例将假性囊肿诊断为单纯腹腔囊肿,2例将假性囊肿误诊为畸胎瘤。结论:胎粪性腹膜炎的超声表现具有一定的特征性,超声诊断准确性较高,可作为新生儿MP的首选检查方法。

Microstructure and Tribological Properties of In-situ Synthesized TiB_2- TiC /Ni Based Composite Coating by Laser Cladding

A TiB2 and TiC particles reinforced Ni based composites coating was prepared on TC4 alloy surface by chemical reaction among Ti, B and C elements using laser cladding technique. Microstructural analysis showed that the sizes of in-situ synthesized TiB2 and TiC particles ranged within 5~10um and l^2um, respectively, while both the two kinds of particles were uniformly distributed in the clad layer. The measurement of microhardness and wear and friction properties indicated that the microhardness of laser clad layer was HV900-1100, being three times of that of the TC4 alloy; the friction coefficient of the laser clad layer in air and in vacuum (10~5 Pa) ranged within 0.2-0.3 and 0.3-0.5, respectively; the wear rate in terms of mass loss was considerably lower than that of the TC4 alloy both in air and in vacuum environment.