Prenatal prediction of childhood-onset spinal muscular atrophy (SMA) in Turkish families

Childhood-onset spinal muscular atrophy (SMA) is one of the most common neurodegenerative genetic disorders. SMN1 is the SMA-determining gene deleted or mutated in the majority of SMA cases. There is no effective cure or treatment for this disease yet. Thus, the availability of prenatal testing is important. Here we report prenatal prediction for 68 fetuses in 63 Turkish SMA families using direct deletion analysis of the SMN1 gene by restriction digestion. The genotype of the index case was known in 40 families (Group A) but unknown in the remaining 23 families (Group B). A total of ten fetuses were predicted to be affected. Eight of these fetuses were derived from Group A and two of these fetuses were from Group B families. Two fetuses from the same family in Group A had the SMNhyb1 gene in addition to homozygous deletion of the NAIP gene. One fetus from Group A was homozygously deleted for only exon 8 of the SMN2 gene, and further analysis showed the presence of both the SMN1 and SMNhyb1 genes but not the SMN2 gene. In addition, one carrier with a homozygous deletion of only exon 8 of the SMN1 gene was detected to have a SMNhyb2 gene, which was also found in the fetus. To our knowledge, these are the first prenatal cases with SMNhyb genes. Follow-up studies demonstrated that the prenatal predictions and the phenotype of the fetuses correlated well in 33 type I pregnancies demonstrating that a careful molecular analysis of the SMN genes is very useful in predicting the phenotype of the fetus in families at risk for SMA. Copyright © 2002 John Wiley & Sons, Ltd.     

斜拉索风雨激振的形状记忆合金半主动控制数值模拟分析

斜拉索风雨激振的控制是斜拉桥工程的关键技术难题之一。本文利用轴向设置的形状记忆合金(ShapeMemory Alloy,SMA)作动器,对斜拉索的风雨激振进行了半主动控制数值模拟分析,控制规则采用KOBORI开关控制。数值分析结果表明,SMA半主动控制可有效的控制拉索的风雨激振;SMA的设置长度及初始的应变大小对控制效果有较大的影响,SMA长度越长,初始应变越大,其控制效果越佳。对由SMA控制引起的拉索张力变化做了分析,其张力的变化很小,在可接受的范围内。研究表明,SMA作动器在参数非理想时控制效果可能有所降低,但控制的稳定性良好。     

Comparison between controlled landfill reactor and conditioned landfill bioreactor

Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste (MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature decomposing MSW. The results of waste biodegradation were compared with that of the leachate-recirculated landfill simulator and conservative sanitary landfill simulator. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown. An obvious enhancement of effective disposal from conservative sanitary landfill (CSL) simulator, to the leachate-recirculated landfill (LRL) simulator and to the conditioned bioreactor landfill(CBL) simulator would be noted, through displaying the compared results of solid waste settlement, heavy, metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio.     

Prenatal prediction in families with autosomal recessive proximal spinal muscular atrophy (5q11.2–q13.3): Molecular genetics and clinical experience in 109 cases

Prenatal prediction in families at risk for autosomal recessive proximal spinal muscular atrophy (SMA) mainly of type I is often requested due to the high incidence and the fatal outcome of the disease. So far, only indirect genotype analysis can be performed in SMA families, since the gene has not yet been identified. We present our experience of 109 prenatal diagnoses obtained in 91 families by use of single- and multi-locus polymorphic microsatellites of the region 5q11.2–q13.3. The marker combinations and specific features of the closest microsatellites are described in detail. From 137 requests for prenatal prediction of SMA between October 1991 and August 1994, 28 families were excluded, mostly because the clinical diagnosis was uncertain or doubtful. Others had to be classified as ‘SMA-variants’ or showed autosomal dominant transmission of SMA. Of the 109 prenatal diagnoses performed, 29 fetuses were diagnosed to be at high risk (>99 per cent) of developing the disease, while in seven additional pregnancies no exact prediction could be made due to a recombination event in one parental haplotype. Altogether, recombinations between closely flanking markers were observed in 14 cases. In 35 cases, the parents decided to terminate the pregnancy. Of the remaining pregnancies, 32 could be followed beyond term. All infants were reported to develop normally without signs of SMA. Two children were born with transverse reduction defects of one hand, which was most likely related to early chorionic villus sampling at 9 and 10 weeks' gestation. No further abnormalities could be detected. The limits of indirect genotype analysis and the problems of diagnostic accuracy and heterogeneity of proximal SMA are discussed.     

SMA绞线-叠层橡胶复合支座结构的动力反应

为了改进现有普通叠层橡胶支座的隔震效果，利用形状记忆合金的超弹性，将SMA绞线加入叠层橡胶支座中，形成了SMA绞线-叠层橡胶复合支座。分析了SMA绞线-叠层橡胶复合支座的工作原理，建立了其力学分析模型，并进行了应用SMA绞线-叠层橡胶复合支座的结构动力反应分析，导出了加速度衰减比尺。与位移放大比凡的理论形式，并利用具体算例，研究了频率比和阻尼比对结构隔震效果的影响。结果表明，频率比越大，阻尼比越小，隔震效果越好。     

三种垃圾填埋场单元模拟器对废物降解的对比试验

在最佳pH值、水分含量和反应温度下,比较了生物模拟器(CBL)和渗滤液回灌的模拟器(LRL)及传统卫生填埋场(CSL)的模拟器的沉降率、产气率和甲烷百分比、生化需氧量和化学需氧量等有机负荷、可生化降解性、重金属浓度和特定甲烷菌活度(SMA)的变化趋势.结合SMA的变化和产气峰值的时间,可以得出脂肪酸和糖类甲烷菌引起了第一次产气峰值,蛋白质和脂类甲烷菌催生了第二次产气峰值.CSL、LRL、CBL的沉降率分别为7.1%、43.3%和60.3%,产气率CBL最高可达1.26m³/d, LRL最高0.92m³/d, CSL则没有峰值,甲烷含量CBL稳定在73%,LRL稳定在51%,CSL含量很低且不稳定,SMA,有机负荷,有机负荷可生化降解性BOD/COD_Cr均为CBL表现最佳,可见生物处理效果上,生物反应器填埋场具有独特的优势和快速降解的作用.     

Impact of alkaline-hydrolyzed biosolids (Lystek) addition on the anaerobic digestibility of TWAS in lab – And full-scale anaerobic digesters

The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste activated sludge (TWAS) was evaluated in a lab- and full-scale anaerobic digester. The overall findings of this study emphasize the beneficial impact of Lystek addition to the lab- and full-scale anaerobic digesters in terms of enhanced biogas production and increased volatile suspended solids reduction (VSSR) efficiency. Lystek added at 4% by volume to TWAS increased the methane yield from 0.22 to 0.26 L CH₄/g VSS_added at an solids retention time (SRT) of 10 days, and from 0.27 to 0.29 L CH₄/g VSS_added at an SRT of 15 days. Furthermore, the VSSRs of 37% and 47% were observed for the TWAS, and the TWAS with 4% Lystek, while at an SRT of 15 days, the observed VSSR were 49% and 58%, respectively. The lab-scale study showed that the influence of Lystek addition on methane yield and solids destruction efficiencies was more pronounced at the shorter SRT, 20% enhancement (SRT of 10 d) vs. 9% enhancement (SRT of 15 d) for methane yield, and 27% (SRT of 10 d) vs. 22% (SRT of 15 d) for VSS destruction efficiency improvement. Furthermore, addition of 4% of Lystek to the feed of the full-scale anaerobic digester at St. Marys wastewater treatment plant (WWTP) resulted in a 50% increase in the average specific methanogenic activity and 23% increase in methane yield of the biochemical methane potential tests after eight months. The results showed that Lystek degradation kinetics were 40% faster than the TWAS, as reflected by first order kinetic coefficients of 0.053 d^?1 and 0.073 d^?1 for TWAS and Lystek at an SRT of 10 days.     

AnMBR用于餐厨垃圾和剩余污泥共发酵的性能研究

通过连续实验和活性实验,系统地研究了厌氧膜生物反应器（AnMBR）在不同有机负荷（OLR）条件下处理餐厨垃圾和剩余污泥的效率、稳定性及动力学特征.结果表明,AnMBR在各工况下（OLR：3.22~12.92gCOD/（L·d））能够稳定运行.其中在OLR为6.48gCOD/（L·d）时运行性能最优,其甲烷产量为（4335±2）mL/d,甲烷产率为（361.2±0.2）mLCH₄/gCOD_removal,COD的去除率维持在（98.6±0.9）%,pH值稳定在7.71±0.03.当OLR超过12.92gCOD/（L·d）,反应器内挥发性脂肪酸（VFA）达到了6108mgCOD/L.膜污染以滤饼层污染为主;利用高通量测序（HTS）探究了系统中微生物的演变情况,Levilinea菌是优势细菌属,在OLR为6.48gCOD/（L·d）时其相对丰度最高（20.1%）,Methanosarcina菌是优势古菌属,随着OLR增加相对丰度均维持在67%以上;比产甲烷活性实验表明随着OLR的增加,产甲烷菌对乙酸的降解能力不断提高.研究结果将为AnMBR处理餐厨垃圾和剩余污泥共发酵系统的最优工况选择提供参考依据.     

形状记忆合金丝-橡胶支座钢框架隔震效果分析

根据作者开发研制的形状记忆合金丝一橡胶复合支座，建立了传统抗震结构和两种不同支座隔震结构体系的运动方程，并对某个实际工程四层钢框架结构进行了数值模拟，分析其在阪神波和El Centro波作用下的时程反应。研究表明，SMA丝一橡胶复合支座是一种很有效的隔震装置，将它用于钢框架结构，能有效地减小结构的位移、速度及加速度时程反应，而对于加速度峰值较大的阪神波的隔震效果更为明显，说明该复合支座能有效地提供罕遇地震作用下钢结构的隔震效果。     

Prenatal activity of a fetus with early-onset,severe spinal muscular atrophy

A case of early-onset, severe spinal muscular atrophy is reported. Normal fetal breathing movement patterns and heart rate accelerations were observed in spite of the severe hypotonia evident at birth.