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We analysed maternal serum human chorionic gonadotropin (hCG) in 16 pregnancies with fetal abdominal wall defects previously identified prenatally by elevated maternal serum alpha-fetoprotein (AFP) or at birth. The AFP levels had a mean of 6·38 MOM (range 0·34–15·65), as expected with these defects. The hCG levels had a mean of 1·82 MOM (range 0·23–4·11). The hCG levels in five pregnancies (31·25 per cent) were above 2·30 MOM. Elevated levels of hCG may be associated with fetal abdominal wall defects. 相似文献
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Eighty-eight cases of abdominal wall defect with and without other lesions were ascertained by reviewing all labour room records in the West of Scotland, all surgical admissions to the Royal Hospital for Sick Children, Yorkhill, and all post mortems at Royal Hospital for Sick Children between 1978 and 1981. The affected cases comprised 39 terminations of pregnancy (17 of anterior abdominal wall defect without neural tube defect). 20 spontaneous stillbirths and 29 livebirths. All 10 cases of body stalk anomaly, 37.5 per cent of 16 gastroschisis cases and 53 per cent of 62 exomphalos cases had additional severe abnormalities. Abnormal karyotypes were present in seven out of 19 exomphalos cases but all karyotypes from 10 gastroschisis and 6 body stalk anomaly cases were normal. No correlation was found between the maternal serum AFP levels, the amniotic AFP levels and acetylcholinesterase results and the size of the lesion. It is proposed that anterior abdominal wall defects detected prenatally should have chromosome analysis and careful ultrasound to exclude associated severe anomalies before coming to a decision about termination. This policy was implemented in six pregnancies complicated by fetal gastroschisis without severe associated anomalies which were identified in the second trimester and continued to term. Immediate surgical repair was achieved in each case, although two of the infants succumbed from later complications of gastroschisis closure and one from respiratory distress syndrome. The remaining three infants made a satisfactory recovery. 相似文献
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膨胀石墨吸附材料在环境保护中的应用 总被引:7,自引:0,他引:7
介绍了膨胀石墨吸附材料的特点、结合国内外研究资料和我们对膨胀石墨吸附性能的研究,重点分析了这种新型吸附材料在环境保护中的各种用途 相似文献
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The role of glomalin, a protein produced by arbuscular mycorrhizal fungi, in sequestering potentially toxic elements 总被引:21,自引:0,他引:21
González-Chávez MC Carrillo-González R Wright SF Nichols KA 《Environmental pollution (Barking, Essex : 1987)》2004,130(3):317-323
Naturally occurring soil organic compounds stabilize potentially toxic elements (PTEs) such as Cu, Cd, Pb, and Mn. The hypothesis of this work was that an insoluble glycoprotein, glomalin, produced in copious amounts on hyphae of arbuscular mycorrhizal fungi (AMF) sequesters PTEs. Glomalin can be extracted from laboratory cultures of AMF and from soils. Three different experiments were conducted. Experiment 1 showed that glomalin extracted from two polluted soils contained 1.6-4.3 mg Cu, 0.02-0.08 mg Cd, and 0.62-1.12 mg Pb/g glomalin. Experiment 2 showed that glomalin from hyphae of an isolate of Gigaspora rosea sequestered up to 28 mg Cu/g in vitro. Experiment 3 tested in vivo differences in Cu sequestration by Cu-tolerant and non-tolerant isolates of Glomus mosseae colonizing sorghum. Plants were fed with nutrient solution containing 0.5, 10 or 20 microM of Cu. Although no differences between isolates were detected, mean values for the 20 microM Cu level were 1.6, 0.4, and 0.3 mg Cu/g for glomalin extracted from hyphae, from sand after removal of hyphae and from hyphae attached to roots, respectively. Glomalin should be considered for biostabilization leading to remediation of polluted soils. 相似文献
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为提高蓝藻在厌氧发酵过程中的资源化利用率,采用高压均质技术处理蓝藻以提高其厌氧发酵产VFAs(挥发性脂肪酸)的效率,通过对蓝藻进行不同压力和pH的高压均质处理,比较处理后蓝藻营养物质的释放情况,并确定该处理的优选运行条件;同时,对未处理蓝藻、高压均质蓝藻、热碱蓝藻进行厌氧发酵试验,评估高压均质处理对蓝藻发酵产酸效果的影响.结果表明:不同条件下高压均质的蓝藻所释放的有机质均较处理前有所提高,其中高压均质的优选条件为压力100 MPa和pH=11,该条件下ρ(SCOD)(SCOD为溶解性化学需氧量)可达22.74 g/L,比对照组提高了52.34倍.在厌氧发酵试验中,高压均质处理在促进有机质释放的同时,还可以提高底物的可生化性,进而提升产酸量.高压均质蓝藻产VFAs的质量浓度最高达8.22 g/L,是对照组的2.16倍.另外,高压均质处理蓝藻的CST(毛细吸水时间)由热碱预处理蓝藻的2 940 s降至1 940 s,减缓了有机质释放带来的脱水性能的恶化趋势.研究显示,高压均质预处理能够提高蓝藻细胞有机质释放、改善碳源可生化性、促进厌氧发酵产酸量,并且降低了分离回收碳源的难度. 相似文献
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