Prenatal diagnosis of partial agenesis of the corpus callosum in a fetus with thanatophoric dysplasia type 2

A fetus with thanatophoric dysplasia type 2 (TD2) associated with cloverleaf skull and abnormal development of the corpus callosum is reported. This case represents the first prenatal direct visualization of a partial agenesis of the corpus callosum (ACC) using high-resolution ultrasonography and colour power Doppler, which was confirmed by post-mortem magnetic resonance imaging (MRI). The causal link between cloverleaf skull in TD and partial ACC is discussed. Copyright © 2002 John Wiley & Sons, Ltd.     

Chondrodysplasia punctata (CDP) with features of the tibia-metacarpal type and maternal phenytoin treatment during pregnancy

We describe a 2-year-old boy with chondrodysplasia punctata (CDP). The boy was exposed to phenytoin, in combination with carbamazepine, during pregnancy. There has been previous evidence for a connection between phenytoin exposure during pregnancy and chondrodysplasia punctata. The boy had clinical and some radiological characteristic features of CDP, of the tibia-metacarpal type. We know of no other report on a child exposed to phenytoin during pregnancy who developed CDP of this type. Copyright © 2002 John Wiley & Sons, Ltd.     

Types of Ontogeny and Territorial Distribution of Small Rodents

In small rodents, differences in the average home range size, depending on the type of ontogeny and animal sex, have been revealed. The dynamics of changes in the spatial structure of populations during the breeding season are described.     

折弯机通用组合上模结构的改进和设计

通过对新、旧2种折弯机组合上模从工艺结构、受力分析、设计要点及调节使用等方面进行全面的比较和分析,提出一种新的、合理的上模结构——偏心销式分段有量度调节结构的折弯机组合上模.     

Prioritizing occupational injury prevention in the construction industry: injury severity or absence?

PROBLEM: National occupational injury prevention goals often prioritize the reduction of serious injuries. This study analyzed whether this prioritization is credible in respect to lost-time injuries and short and long term work absence, and the implications this has for injury severity-based versus injury absence-based prevention approaches. METHOD: The data consisted of national and work-site specific injury and absence data from construction workers in Denmark, including workers from the Copenhagen Metro construction sites, during the period 2000-2001. RESULTS AND IMPACT ON INDUSTRY AND GOVERNMENT: Absence length was significantly dependent on the type of injury. Sprains and strains were most prevalent and accounted for approximately one third of injuries and absence. Fractures accounted for one sixth of injuries and the greatest proportion of long-term absence. The results give credibility to the need for targeting sprains and strains in injury and absence prevention initiatives.     

Particle concentration effect in adsorption/desorption of Zn（Ⅱ） on anatase type nano TiO2

Adsorption/desorption in a new Zn(II)-TiO2 adsorption system was investigated at different particle concentrations (Cp). TEM, SEM and XRD analyses revealed that the TiO2 particles were an aggregation of nano-sized (approximately 10 nm) pure anatase-type TiO2. Adsorption experiments were carried out with particle concentrations of 100, 400 and 1000 mg/L, and their adsorption isotherms were found to decline successively, showing an obvious Cp effect. Desorption experiments indicated that adsorption in this system was irreversible, and the irreversibility increased with increasing Cp. These phenomena could be explained by the MEA (metastable equilibrium adsorption) theory and the Cp effect could be modeled well with an MEA-Freundlich-type Cp effect isotherm equation. This study may help understand environmental behavior of contaminants on ultrafine natural particles.     

Natural under-canopy regeneration and height-age structure of small-leaved linden (<Emphasis Type="Italic">Tilia cordata</Emphasis> Mill.) undergrowth in water-conservation forests around Pavlovskoe Reservoir,Ufa River

Natural regeneration and the height-age structure of small-leaved linden (Tilia cordata Mill.) under a forest canopy were studied with regard to specific features of forest typology on the Ufa Plateau. For the first time, the height-age structure of linden undergrowth was analyzed by an anatomical method, which allowed accurate determination of the actual plant age and linear increment. The results of this analysis made it possible to reveal three periods in the development of linden undergrowth with respect to the linear growth rate and abundance of plants. More successful regeneration of linden was observed in open elements of relief.     

上海都市农业村域地表水非点源氮素的时空分异特征

为研究平原地区都市农业区域地表水非点源氮素的时空分异特征,揭示非点源氮污染对地表水环境的影响,连续监测了上海南汇新场镇果园村地表水中总氮和无机"三氮"(硝态氮、铵态氮和亚硝态氮)的含量.结果表明:①水文期和土地利用类型共同影响地表水中氮素的空间分布.受果园影响的地表水中硝态氮(NN)浓度较高,铵态氮(AN)浓度较低,各监测点氮素浓度在多雨期差异较大,在少雨期差异较小;受居民区和工厂影响的地表水中NN和AN浓度相差不大,各监测点氮素浓度在多雨期和少雨期差异都较大.②冬、夏季风风向可能影响果园村地表水中氮素的空间分布.③春雨期总氮(TN)、NN和AN的空间变异大,梅雨期和冬季少雨期略大于秋雨期和盛夏少雨期;亚硝态氮(SNN)与之相反.④5月溶解性有机氮(DON)是果园区地表水中氮素的主要存在形式,占TN的质量分数达到76.1%;其它季节则以溶解性无机氮(DIN)为主,占TN的质量分数平均达到83.2%.⑤果园区NN的季节变异比居民区大,居民区AN和TN的季节变异比果园区大.     

徐州市工业固体废物产生种类主成分分析研究

文章在介绍主成成分分析方法的原理基础上,利用SPSS统计软件对徐州市1996年至2000年工业固体废物产生种类及其量8个指标原始数据进行主成分分析,提取了占总方差81.126%能够反映原始数据的绝大部分信息的二个主成分:第一主成分和冶炼废渣、粉煤灰、炉渣密切相关,第二主成分和尾矿、煤矸石密切相关。结果表明徐州市电力、钢铁和煤矿开采行业工业固体废物产生种类及产生量变化趋势与徐州市经济发展方式相吻合,为徐州市工业固体废物污染源头控制提供决策指导。