Trisomy 15 mosaicism owing to familial reciprocal translocation t(1;15): implication for prenatal diagnosis

We describe a 4-year-old female child with severe global mental retardation, myoclonic epilepsy, proximal hypotonia and dysmorphisms, whose prenatal diagnosis following amniocentesis revealed a constitutional female karyotype carrying a t(1;15)(q10;p11) familial reciprocal translocation. Post-natal high-resolution karyotype, Fluorescence in situ hybridization (FISH) screening for subtelomeric rearrangements, VNTR search for UPD15 in the blood and fibroblast, and WCP1 and 15 in the mother, failed to provide an explanation for the complex clinical phenotype of the proband. Since the pachytene configuration of the translocated chromosomes defines a high probability of 3:1 segregation, an extensive workup was undertaken to look for a possibly cryptic mosaicism. Four percent of the cells with trisomy 15 was found in the peripheral blood lymphocytes examined by classical cytogenetic technique and interphase FISH analysis. The clinical features associated with cryptic trisomy 15 mosaicism and the problems concerning prenatal diagnosis and genetic counselling for carriers of translocations at high risk of 3:1 segregation are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Radiation Effects on Blends of Poly(ε-Caprolactone) and Diatomites

Poly(-caprolactone) (PCL) was blended with diatomaceous earth (diatomite) and irradiated with -rays to introduce cross-linking between PCL molecules or both components. The unwashed diatomite containing a little of a volatile component showed high efficiency of introduction of cross-linking, whereas that with no volatile component showed low efficiency of introduction of cross-linking. Elongational viscosity, melt viscosity, and modulus of PCL/diatomite blend irradiated at various doses were significantly improved. Enzymatic degradation of the PCL/diatomite blend became faster than that of the PCL, though that of the blend irradiated became slower.     

Morphophysiological Rearrangements in Fish in Response to Pollution (in the Light of S.S. Shvarts' Theory)

The results of a study on morphophysiological variation in fish inhabiting a subarctic lake exposed to chronic industrial pollution are described using an example of cisco, Coregonus lavaretus. It is shown that indices of the heart, liver, kidneys, gills, and fatness in these fish are increased significantly and have retained increased values for the past 20 years. The observed changes are analyzed on the basis of biochemical data. The results of studies on the dynamics of hematological parameters in fish are used for characterizing the development of toxicosis. Adaptive rearrangements associated with an increase in the metabolic rate and the activation of protective systems in the fish are explained in the context of S.S. Schvarts' concept. The idea is proposed that the additional energy cost of detoxification may be responsible for morphophysiological variation in fish under conditions of water pollution.     

钠盐量影响下DD6单晶高温合金的高温热腐蚀规律研究

目的 开展镍基单晶高温合金DD6在950 ℃下的热盐腐蚀试验(95%Na2SO4+5%NaCl)，探明涂盐量和涂盐方式(周期涂盐和单次涂盐)对DD6高温热腐蚀的影响规律和机理。方法 结合扫描电子显微镜、X射线能量色散谱、X射线衍射等设备，对不同涂盐量及涂盐方式下DD6的表面及横截面形貌进行观察分析，分析不同涂盐量和涂盐方式下DD6的高温热腐蚀机理。结果 DD6在950 ℃下主要发生碱性熔融热腐蚀，同时伴随氧化、硫化和氯化等过程。高温热腐蚀使得DD6合金表面生成的保护性氧化膜被熔融态的腐蚀介质破坏，导致O、S、Cl等外部元素通过氧化膜的缺陷进入DD6基体中，在合金的亚表面发生内氧化、内硫化以及内氯化反应，横截面上出现明显的腐蚀层，其主要由氧化物以及硫化物组成。随着热腐蚀的进行，DD6表面物质发生了剥蚀，沉积盐量的增加导致剥蚀现象越加严重，合金内部致密的组织结构也被破坏，横截面上出现了大量孔洞、裂纹等缺陷。在相同涂盐量下，周期涂盐法使得DD6的腐蚀程度高于单次涂盐法。结论 DD6高温热腐蚀行为与涂盐量及涂盐方式密切相关，相同涂盐方式下，涂盐量越大，DD6热腐蚀更加严重。涂盐量一定时，周期涂盐法使得DD6的热腐蚀剧烈程度大于单次涂盐法，且DD6在上述热腐蚀条件下均发生剥蚀破坏。