Changes in fetal heart rate pattern after intrauterine paracentesis in one twin with meconium peritonitis

We report a case of in utero paracentesis of ascites in a fetus with meconium peritonitis due to volvulus at 34 weeks which resulted in the correction of an abnormal fetal heart rate pattern and enabled vaginal delivery by preventing abdominal dystocia. The intrauterine intervention also helped to establish the diagnosis and potentially reduced the respiratory compromise after birth. Copyright © 2001 John Wiley & Sons, Ltd.     

Aerosol optical properties under different pollution levels in the Pearl River Delta (PRD) region of China

To clarify the aerosol hygroscopic growth and optical properties of the Pearl River Delta(PRD)region,integrated observations were conducted in Heshan City of Guangdong Province from October 19 to November 17,2014.The concentrations and chemical compositions of PM_(2.5),aerosol optical properties and meteorological parameters were measured.The mean value of PM_(2.5) increased from less than 35(excellent) to 35-75 μg/m~3(good) and then to greater than 75 μg/m~3(pollution),corresponding to mean PM_(2.5) values of 24.9,51.2,and 93.3 μg/m~3,respectively.The aerosol scattering hygroscopic growth factor(f(RH = 80%)) values were 2.0,2.12,and 2.18 for the excellent,good,and pollution levels,respectively.The atmospheric extinction coefficient(σext)and the absorption coefficient of aerosols(σ_(ap)) increased,and the single scattering albedo(SSA)decreased from the excellent to the pollution levels.For different air mass sources,under excellent and good levels,the land air mass from northern Heshan had lower f(RH) and σ_(sp) values.In addition,the mixed aerosol from the sea and coastal cities had lower f(RH) and showed that the local sources of coastal cities have higher scattering characteristics in pollution periods.     

Effect of graphene oxide exposure on intestinal Wnt signaling in nematode Caenorhabditis elegans

Exposure to engineered nanomaterials(ENMs), such as graphene oxide(GO), can potentially induce the response of various molecular signaling pathways, which can mediate the protective function or the toxicity induction.Wnt signaling pathway is conserved evolutionarily in organisms.Using Caenorhabditis elegans as an in vivo assay model, we investigated the effect of GO exposure on intestinal Wnt signaling.In the intestine, GO exposure dysregulated Frizzled receptor MOM-5, Disheveled protein DSH-2, GSK-3(a component of APC complex), and two β-catenin proteins(BAR-1 and HMP-2), which mediated the induction of GO toxicity.In GO exposed nematodes, a Hox protein EGL-5 acted as a downstream target of BAR-1, and fatty acid transport ACS-22 acted as a downstream target of HMP-2.Functional analysis on HMP-2 and ACS-22 suggested that the dysregulation of these two proteins provides an important basis for the observed deficit in functional state of intestinal barrier.Our results imply the association of dysregulation in physiological and functional states of intestinal barrier with toxicity induction of GO in organisms.     

不同入流类型对生态流量管理效果的影响

河流生态流量管理对于保护下游生态系统具有非常重要的作用。在水库生态调度的研究中,为了给不同流量时期提供不同生态流量,下游生态流量管理越来越复杂化。人们倾向于采用更复杂的生态流量管理来改善生态水文情势。然而,除了生态流量管理,水库入流类型也会影响生态水文情势,进而影响生态流量管理效果。因此,研究不同入流类型对生态流量管理效果的影响,有助于在考虑水库调度成本的情况下,在水库生态调度之前更好地选择生态流量管理方案。通过分析全球径流,总结出3种入流类型。为了对比不同的生态流量管理方案,采用了4种通用生态流量管理方案。结果表明:当水库入流量年内分配较均匀、流量曲线变换平缓时,生态流量管理方案的改变不会影响河流生态水文情势,即这种类型的入流对生态流量管理方案不敏感。     

基于空间适宜性评价和人口承载力的贵溪市中心城区城市开发边界的划定

城市开发边界的划定能够合理引导城市空间的有序发展,控制其无序蔓延。论文以典型的资源型城市贵溪市为研究区,从空间适宜性评价、人口承载力、城市规模以及城市总体规划和土地利用总体规划（简称“两规”）衔接等方面探索有效的城市开发边界划定方法。空间适宜性评价综合考虑自然、空间可达性和生态条件,运用聚类分析法确定区域内不宜作为开发建设的生态底线区域和适宜建设开发区域的高低等级,以此确定城市开发边界的发展方向。通过灰色预测GM(1,1)模型预测研究区2020年人口总量,并基于土地资源和水资源承载力验证当地所能容纳的最大人口总量,同时确定城市规模和划定城市开发边界。以空间适宜性评价、人口承载力、城市规模预测、两规衔接和空间形态控制等方法倒逼缩减建设用地,从而划定城市发展的刚性和弹性增长边界。     

Ecotoxicity evaluation of Cu- and Fe-CNT complexes based on the activity of bacterial bioluminescence and seed germination

The toxic effects of the composites of Fe~0 and Cu~0 with different percentages of CNTs were examined based on the activity of bacterial bioluminescence and seed germination. In terms of the EC_50 values, the toxic effects of Cu~0 on bacterial bioluminescence and seed germination were approximately 2 and 180 times greater than that of Fe~0, respectively. The toxicity increased with increasing CNT content in the Cu-CNT mixtures for both organisms,whereas opposite results were observed with Fe-CNT mixtures. The mean toxic effects of Cu-CNT(6%) were approximately 1.3–1.4 times greater than that of Cu-CNT(0%), whereas the toxic effects of Fe-CNT(6%) were approximately 2.1–2.5 times lower than that of Fe-CNT(0%) for both the bioluminescence activity and seed germination. The causes of this phenomenon are unclear at this point. More research will be needed to elucidate the mechanism of the toxicity of nano-mixture materials and the causes of the different patterns of toxicity with Cu-and Fe-CNT mixtures.     

石墨烯在防腐涂料中的研究进展及应用

简要叙述了石墨烯结构性能以及当前主流制备石墨烯的方法。概述了最近几年来石墨烯在防腐涂料中的研究进展情况,包括石墨烯在涂料中的添加量、分散技术、原位改性等对涂料性能的影响。研究表明,在涂层中分散均匀添加量适中的石墨烯可以对防腐涂料性能有较大的提升,探讨了石墨烯在防腐涂层中的应用机理,同时对石墨烯防腐涂料的应用发展进行了展望。     

Prediction of Leachate Level in Kimpo Metropolitan Landfill Site by Total Water Balance

Kimpo metropolitan landfill has received various kinds of wastessince January 1992. The leachate level was measured to be 10.3 m in May 1995 and the level increased to 12.2 m in August 1996. Therefore, to prove the reason for the increasing leachate level, we calibrated hydraulic conductivity of each waste andintermediate layer using the HELP (Hydrologic Evaluation ofLandfill Performance) model. The leachate generation data measured from February 1993 to October 1995 was used in the model calibration. As a result of a model calibration, we obtained anaverage infiltration ratio and used this in analysis of the total water balance to predict elevation of leachate level. Main causes of the elevation of the leachate level were the high water content of the waste and the degradation of the leachate-drainage system caused by the subsidence of a naturalbarrier layer.     

基于AHP-MF模型的用户群节水指标体系研究

从分析影响用户群节水的因素及其构成关系入手,根据专家长期节水工作的经验,利用层次分析法对用户群节水指标进行优选,并提出全面的定量化和定性化的层次结构评价模式和总体评价方法.首先构建用户群节水的层次分析结构模型及判断矩阵,应用Matlab6.5计算出各判断矩阵的最大特征值及其特征向量,并检验判断矩阵的一致性,继而确定出各指标的权重;其次,应用Fuzzy统计的方法对陕西2006年度高校用户群的节水情况进行评价,并为节水工作提供建设性意见.     

连续速度场解析圆管辊拔减径

此文利用连续速度场解析了圆管辊拔减径问题的拔制力,并获得上界解析解.该解与圆管辊拔实验结果比较表明,两者吻合较好.因而,该解析解可在工程上计算圆管辊拔拔制力时推广应用.