Evidence of a second gamete fusion after the first cleavage of the zygote in a 47,XX, + 18/70,XXX, + 18 mosaic. A remarkable diploid-triploid discrepancy after CVS

A 70,XXX, +18 karyotype was found by chorionic villus sampling, while the fetal fibroblast culture of the affected fetus revealed a 47,XX,+ 18 karyotype. From several possible mechanisms, we assume that a second gamete fusion occurred after the first cell division of the zygote. According to this interpretation, the mosaicism arose in very early pregnancy (at the two-cell stage). This discrepancy can therefore be explained by selection pressure, due to the differentiation processes in the embryonic tissues.     

林丹(γ-六六六)在土壤中的吸附性与其在土壤和小麦中残留量的关系

本文利用~(14)C—林丹研究了γ-六六六在不同土壤中的吸附性及其在土壤和小麦中残留量的关系。试验表明,γ-六六六在土壤中的吸附率与土壤中的有机质含量、可萃取铝含量和酸性等均有密切关系。同时,环境温度对吸附率也有一定影响。通过~(14)C—林丹在不同土壤和小麦植株中残留量的测定,证明土壤中γ-六六六的吸附率、小麦对土壤中r-六六六的吸收率以及γ-六六六在土壤和小麦中的残留量相互之间均有明显的相关性。为此,本研究不仅摸清了某些影响土壤吸附γ-六六六和小麦吸收γ-六六六的理化因子,同时,对用土壤某些理化性质的测定值来预测栽培试验时土壤和小麦中六六六的残留水平提供了一个途径。     

Metamorphic evolution of eclogite and associated garnet-mica schist in the high-pressure metamorphic Maksyutov complex, Ural, Russia

Metasedimentary garnet-mica schists are interlayered with metabasic garnet–omphacite schists and enclose eclogite boudins in the high-pressure metamorphic Maksyutov complex in the Southern Urals, Russia. These three rock types were investigated in one outcrop and compared chemographically and thermobarometrically. The Fe/Mg distributions between garnet rim–omphacite and garnet rim–phengite pairs indicate different equilibration temperatures for the three samples, with the lowest temperature (500°C, >1.5 GPa) for the eclogite boudin, an intermediate temperature (630°C, >1.7 GPa) for the foliated eclogite and the highest temperature (650°C, >1.7 GPa) for the garnet-mica schist. The garnets in garnet-mica schist enclose abundant chloritoid relics and the Fe/Mg distribution between chloritoid and garnet records an earlier high-temperature stage (650°C, >2.0 GPa) before the garnet rim–phengite temperatures were reached. Together with some minimum- and maximum-pressure estimates three different prograde pressure–temperature paths and a common retrograde metamorphic evolution are interpreted from the chemographic and thermobarometric data. The different early metamorphic evolutions and conditions confirm the variability of protoliths, which are also indicated by different U/Pb zircon and rutile ages.     

絮凝法处理纸浆漂白废水的研究

研究了无机絮凝剂ＰＡＣ，ＰＳＡ，ＰＥＳ，ＭｇＣｌ２，ＣａＯ及其与有机高分子絮凝剂ＣＧＡ复全使用对两种不同工艺漂白废水的混凝处理特性，结果表明，水质１ＣＯＤｃｒ，ＡＯＸ去除率分别为６３．２％，４５．３％，水质２ＣＯＤｃｒ，ＡＯＸ去除率达７３．１￥％，５３．４％。化钙与碳酸钠具有相同的降解ＡＯＸ能力，硫离子在中性ｐＨ条件下可显著提高ＡＯＸ的去除率。     

克山病病区低硒粮喂养的豚鼠红细胞内Na~+浓度变化的研究

豚鼠分别喂以克山病病区粮(低硒)和非病区粮(硒含量正常),借助合成的D_Y(PPP)_2~(-7)位移试剂用XL-400NMR谱仪直接测试完整红细胞内Na~+的NMR谱,并定量计算细胞内Na~+浓度,发现低硒的病区粮饲养的豚鼠红细胞内Na~+浓度显著高于正常组;病区粮喂养的豚鼠红细胞在老化条件下细胞溶血比非病区严重。     

Limb reduction and chorion villus sampling

Upper limb reduction was diagnosed by ultrasound scan at 17 weeks after chorion villus sampling at 9 weeks' gestation. Pregnancy was terminated and necropsy confirmed limb reduction in an otherwise normal fetus. The relationship of limb reduction to amniotic band syndrome is discussed.     

选择性离子交换法脱除水中NH3-N

采用储量较大的黑龙江省嫩江天然斜发沸石,对其脱除NH_3-N的能力、预处理及洗脱再生方法、交换平衡、交换动力学等进行系统的研究,并对沸石床层的交换过程进行数学模型计算。     

Climate change and temperature-dependent biogeography: oxygen limitation of thermal tolerance in animals

Recent years have shown a rise in mean global temperatures and a shift in the geographical distribution of ectothermic animals. For a cause and effect analysis the present paper discusses those physiological processes limiting thermal tolerance. The lower heat tolerance in metazoa compared with unicellular eukaryotes and bacteria suggests that a complex systemic rather than molecular process is limiting in metazoa. Whole-animal aerobic scope appears as the first process limited at low and high temperatures, linked to the progressively insufficient capacity of circulation and ventilation. Oxygen levels in body fluids may decrease, reflecting excessive oxygen demand at high temperatures or insufficient aerobic capacity of mitochondria at low temperatures. Aerobic scope falls at temperatures beyond the thermal optimum and vanishes at low or high critical temperatures when transition to an anaerobic mitochondrial metabolism occurs. The adjustment of mitochondrial densities on top of parallel molecular or membrane adjustments appears crucial for maintaining aerobic scope and for shifting thermal tolerance. In conclusion, the capacity of oxygen delivery matches full aerobic scope only within the thermal optimum. At temperatures outside this range, only time-limited survival is supported by residual aerobic scope, then anaerobic metabolism and finally molecular protection by heat shock proteins and antioxidative defence. In a cause and effect hierarchy, the progressive increase in oxygen limitation at extreme temperatures may even enhance oxidative and denaturation stress. As a corollary, capacity limitations at a complex level of organisation, the oxygen delivery system, define thermal tolerance limits before molecular functions become disturbed.