Prenatal ultrasound diagnosis of amelia

Amelia is a very rare form of limb reduction defect. The incidence of isolated amelia with or without other limb reductions is 0.4 per 100 000 births. We report a cluster of three cases diagnosed prenatally. One was isolated tri-amelia and two were isolated tetra-amelia.     

超声波-光催化联合降解苯酚废水研究

超声降解和光催化降解均为自由基历程的高级氧化技术,同时,超声空化能够改善传质效果,因此,二者耦合能否产生协同效果是值得研究的。本文考察了苯酚溶液的超声降解、光降解、光催化降解、超声-光催化降解以及温度对光降解和光催化降解的影响。结果表明,40kHz,0.4w/cm2的超声波对苯酚没有明显的降解作用,而对光催化降解只有轻微的促进作用。光降解和光催化降解的过程曲线显著不同,但温度对二者均有显著的促进作用。     

Ultrasound enhanced heterogeneous activation of peroxydisulfate by bimetallic Fe-Co/GAC catalyst for the degradation of Acid Orange 7 in water

Bimetallic Fe-Co/GAC （granular activated carbon） was prepared and used as heterogeneous catalyst in the ultrasound enhanced heterogeneous activation of peroxydisulfate （PS, S2O8 2-） process. The effect of initial pH, PS concentration, catalyst addition and stirring rate on the decolorization of Acid Orange 7 （AO7） was investigated. The results showed that the decolorization efficiency increased with an increase in PS concentration from 0.3 to 0.5 g/L and an increase in catalyst amount from 0.5 to 0.8 g/L. But further increase in PS concentration and catalyst addition would result in an unpronounced increase in decolorization efficiency. In the range of 300 to 900 r/min, stirring rate had little effect on AO7 decolorization. The catalyst stability was evaluated by measuring decolorization efficiency for four successive cycles.     

Dwarfism associated with prenatal ventriculomegaly

Two infants with ventriculomegaly diagnosed by ultrasound during the third trimester of pregnancy were noted to have lethal short-limbed dwarfing syndromes at birth. In one instance, a clinical suspicion of hydramnios and in the other follow-up scan for placental localization revealed ventriculomegaly as an unexpected finding. These observations suggest that when ventriculomegaly is detected during prenatal ultrasound evaluation, limb measurements should be included to exclude a dwarfing syndrome as part of the differential diagnosis.     

Prenatal diagnosis of trisomy 20 by chorionic villus sampling (CVS): a case report with long-term outcome

A case of prenatally diagnosed non-mosaic trisomy 20 in cells cultured from a chorionic villus sample (CVS)is presented. The term placental karyotype was also non-mosaic trisomy 20. The karyotype of thenewborn was 46,XY/47,XY,+20 in foreskin cultures and in a second skin culture; blood lymphocyte culture was 46,XY. Aside from diffuse, hypopigmentary swirls along the lines of Blaschko observed on hisextremities and trunk, referred to as hypomelanosis of Ito, the patient is clinically normal at 8¾ years ofage. In addition, he is one of the oldest reported cases of mosaic trisomy 20 confirmed after birth forwhich the clinical outcome has been monitored. This case demonstrates that these trisomy 20 findings are compatible with normal psychomotor development and phenotype. Copyright © 2001 John Wiley & Sons, Ltd.     

超声辅助电催化氧化降解苯酚的研究

对电催化氧化和超声辅助电催化氧化降解苯酚过程中的UV扫描吸收光谱研究表明:在苯酚的氧化降解反应过程中,都有对紫外光有吸收的中间体生成;对吸光度峰值随降解反应时间的变化关系进行非线性最小二乘法拟合(NLSF),发现溶液的相对吸光度峰值的衰减均符合表观零级反应动力学规律,其相应的表观反应速率常数(k0)分别为(0.0051±0.0005)min-1和(0.0052±0.0003)min-1;但超声波对电催化降解苯酚的速度和效果并无显著影响.同时GC-MS也检测到苯酚超声辅助电催化氧化降解60 min后,发现除苯酚仍然存在外,还有中间产物苯酚乙酸酯、甲酸、乙酸,从而证实苯酚在羟基自由基作用下,开环氧化降解生成乙酸和甲酸等小分子有机物,最后降解为二氧化碳和水.     

超声去除垃圾渗滤液中的氨氮

采用超声辐照技术去除垃圾渗滤液中的氨氮.研究结果表明,超声辐照对垃圾渗滤液中的氨氮有很好的去除效果.渗滤液中氨氮超声去除的机理主要是氨氮以游离氨的形式在空化泡内发生高温热解反应,生成氮气和氢气而排出.