Unusual segregation for 11q;22q parental translocation in a triplet pregnancy: Prenatal diagnosis in chorionic villi and amniotic fluid

The prenatal diagnosis of an 11q;22q translocation in a triplet pregnancy detected at the time of chorionic villus sampling (CVS) because of advanced maternal age is reported. Karyo-types obtained from two apparently different CV samples showed the balanced form of translocation, while the one obtained from a third empty sac showed the unbalanced form: 46, XX, −22, + der(22)t(11;22). Second-trimester amniocentesis confirmed the balanced translocation in one of the two viable fetuses and a normal karyotype in the other. The detected karyotypes derived from two different types of meiotic segregation, alternate and adjacent 1. To our knowledge, this is the first reported case of an unbalanced karyotype not due to a 3:1 meiotic segregation of this specific translocation.     

钛合金ZrN耐磨抗冲蚀防护涂层

采用真空多弧镀设备在TC11钛舍金表面沉积超硬耐磨ZrN防护涂层,通过增压气流固体颗粒冲蚀实验评价ZrN涂层的耐磨抗冲蚀性能,划痕仪测试涂层与基体的结合力,SEM、X射线分析涂层组成及观察涂层冲蚀前后表面形貌,盐雾及电化学实验测试涂层耐腐蚀性能。结果表明,ZrN涂层成分主要为（111）择优取向的ZrN相;ZrN涂层不影响钛合金的耐腐蚀性能及疲劳性能;ZrN涂层与基体结合牢固．涂层大大提高了基体的耐磨抗冲蚀性能。     

基于MIKE11与EFDC模型的突发性水污染事故预测模拟研究

通过对沈阳市浑河流域水环境的调查,基于Mike11与EFDC建立浑河流域沈阳段水动力-水质耦合模型,并对突发污染事故进行模拟研究。结果表明,Mike11与EFDC模型应用于浑河流域的预警模型在率定期和验证期的模拟结果均良好,所确定的参数能准确反映河道特征。因此,此预警模型可应用于浑河流域突发性水环境风险应急预测,并且能够对浑河污染物迁移转化过程进行准确模拟预测,模拟结果能够为区域水资源管理和保护提供技术支持,达到流域应急预警功能需求。     

Strictly protected areas are not necessarily more effective than areas in which multiple human uses are permitted

The International Union for Conservation of Nature (IUCN) classifies protected areas into six categories, ranging from strict nature reserves to areas where multiple human uses are permitted. In the past, many researchers have questioned the effectiveness of multiple-use areas, fueling an unresolved debate regarding their conservation value. The literature so far has been inconclusive: although several studies have found that strictly protected areas are more effective, others have found the opposite, and yet others that the two types do not differ. To help resolve this debate, we reviewed the literature on protected areas and conducted our own analysis using > 19 000 terrestrial protected areas worldwide. We found that the differences between strictly protected areas and areas in which multiple human uses are permitted are often small and not statistically significant. Although the effectiveness of protected areas worldwide varies, other factors, besides their assigned IUCN category, are likely to be driving this pattern.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01426-5) contains supplementary material, which is available to authorized users.     

典型区域土壤中PCB-11的污染特征

利用高分辨气相色谱/高分辨质谱法研究了土壤中PCB-11（3,3＇-二氯联苯,CAS 2050-67-1）的污染特征和分布规律,探讨了土壤中PCB-11的污染来源.结果表明,我国一般城市地区（天津、鞍山）和电子垃圾拆解地周边土壤中PCB-11的检出率为100%,PCB-11可能广泛存在于土壤介质中.天津、鞍山、电子垃圾...     

Dynamic relationship between precious metals

We use a relatively new approach to endogenously detect the volatility shifts in the returns of four major precious metals (gold, silver, platinum and palladium) from 1999 to 2013. We reveal that the turbulent year of 2008 has no significant effect on volatility levels of gold and silver however causes an upward shift in the volatility levels of palladium and platinum. Using the consistent dynamic conditional correlations, we show that precious metals get strongly correlated with each other in the last decade which reduces the diversification benefits across them and indicates a convergence to a single asset class. We endogenously detect the shifts in these dynamic correlation levels and reveal uni-directional volatility shift contagions among precious metals. The results show that gold has a uni-directional volatility shift contagion effect on all other precious metals and silver has a similar effect on platinum and palladium. However, the latter two do not matter in terms of volatility shift contagion. Thus, investors that hedge with precious metals should, in particular, monitor the volatility levels of gold and silver.     

广州市主要污染物总量减排环境绩效评价

“十一五”期间,广州市主要污染物COD和SO2排放总量持续下降,经初步核算,2010年COD和S02排放量分别比2005年下降2．7万吨和6．5万吨,减排比例分别达到19．7％和43％,总量减排工作顺利完成。减排对环境改善明显,珠江广州河段主要污染指标浓度值均有所下降,COD年均浓度从2005的20．7毫克／升下降至2010年的13．6毫克／升,下降幅度达34．3％,整体水环境质量得到根本好转;空气环境质量优良率逐年上升,大气主要污染指标年均浓度值基本呈现逐年下降的态势,SO2从2005年年平均浓度为0．053毫克／立方米下降至2010年的0．033毫克／立方米,下降幅度达37．7％,空气质量持续得到好转。     

阳离子型可逆表面活性剂在膨润土上的吸附行为

研究可逆表面活性剂十一烷基二茂铁三甲基溴化铵(FTMA)在膨润土上的吸附机理,并与CTAB进行对比;同时考察土壤关键因子对FTMA吸附的影响.结果表明,FTMA与CTAB在膨润土上的吸附变化规律一致,饱和吸附量为66cmol/kg,约为膨润土1倍CEC,吸附机制主要为阳离子交换作用.不同温度下FTMA吸附等温线均可用Langmuir模型描述,吸附量随温度升高(298→318K),由280.6mg/g增大至350.8mg/g.吸附在8h达到平衡,吸附速率较CTAB慢,并符合准二级动力学方程,化学吸附是主要控制速率步骤.热力学参数计算得出,该吸附是自发吸热过程.随体系离子强度的增大,吸附量下降;共存阳离子对吸附有抑制作用,且影响程度大小为: Ca2+>K+>Na+; pH值对吸附影响较小;腐植酸(HA)的加入促进了FTMA的吸附.     

Global protected-area coverage and human pressure on tidal flats

Tidal flats are a globally distributed coastal ecosystem important for supporting biodiversity and ecosystem services. Local to continental-scale studies have documented rapid loss of tidal habitat driven by human impacts, but assessments of progress in their conservation are lacking. With an internally consistent estimate of distribution and change, based on Landsat satellite imagery, now available for the world's tidal flats, we examined tidal flat representation in protected areas (PAs) and human pressure on tidal flats. We determined tidal flat representation and its net change in PAs by spatially overlaying tidal flat maps with the World Database of Protected Areas. Similarly, we overlaid the most recent distribution map of tidal flats (2014–2016) with the human modification map (HM_c) (range from 0, no human pressure, to 1, very high human pressure) to estimate the human pressure exerted on this ecosystem. Sixty-eight percent of the current extent of tidal flats is subject to moderate to very high human pressure (HM_c > 0.1), but 31% of tidal flat extent occurred in PAs, far exceeding PA coverage of the marine (6%) and terrestrial (13%) realms. Net change of tidal flat extent inside PAs was similar to tidal flat net change outside PAs from 1999 to 2016. Substantial shortfalls in protection of tidal flats occurred across Asia, where large intertidal extents coincided with high to very high human pressure (HM_c > 0.4–1.0) and net tidal flat losses up to 86.4 km² (95% CI 83.9–89.0) occurred inside individual PAs in the study period. Taken together, our results show substantial progress in PA designation for tidal flats globally, but that PA status alone does not prevent all habitat loss. Safeguarding the world's tidal flats will thus require deeper understanding of the factors that govern their dynamics and effective policy that promotes holistic coastal and catchment management strategies.     

HHMHC对Cu2+、Ni2+的萃取性能

以对羟基苯甲酸为原料,通过化学修饰合成得到上沿羧基化的杯[6]芳烃羟肟衍生物,即5,11,17,23,29,35-六羧基-37,38,39,40,41,42-六羟肟酸甲氧基杯[6]芳烃(HHMHC),采用IR对其结构性能进行表征,并探讨了溶液初始pH值、初始重金属离子(Cu2+、Ni2+)浓度、萃取时间、温度等因素对HHMHC萃取重金属离子的影响.结果表明,在温度为30℃时HHMHC萃取Ni2+和Cu2+的最佳pH值分别为5.0、6.0,萃取平衡时间均为30min.用准二级动力学模型(R2>0.99)和Freundlich等温模型(R2>0.999)均可较好的拟合其萃取过程,通过计算萃取过程的热力学参数,得到Gibbs自由能(ΔG0)和焓变(ΔH0)均小于0,表明萃取反应是一个自发的放热反应.通过红外光谱图分析和考察溶液pH值对萃取分配比的影响,探讨HHMHC萃取Cu2+、Ni2+的机理,结果表明此萃取过程除了存在阳离子交换机理外,还存在与冠醚萃取相同的离子配位萃取,参与配位作用的主要是羟肟基团(–CONHOH).