Pathophysiology,diagnosis and management of prenatal upper tract dilatation

Upper tract dilatation presenting as renal pelvis dilatation with or without ureteric dilatation is one of the more common abnormalities detected on prenatal ultrasound scanning. The majority of cases are due to pelvi-ureteric and vesico-ureteric junction anomalies, and vesico-ureteric reflux. Prenatal diagnosis with ultrasound may be aided by biochemical analysis of fetal blood and urine. The natural history of prenatally detected abnormalities remains under review. Precise diagnosis, and therefore prognosis, may not be made until after birth. Copyright © 2001 John Wiley & Sons, Ltd.     

Prenatal diagnosis of exophytic nevus sebaceous of the scalp

Nevus sebaceous is a complex hamartoma most commonly found on the scalp, face, and neck and is often present at birth, although some may be diagnosed later in infancy. We report the first prenatal diagnosis of isolated nevus sebaceous that presented at 19 weeks' gestation as a large and exophytic tumor of the scalp. This case emphasizes the crucial role of ultrasound examination performed with high-frequency probes, which revealed associated diffuse lesions of the face. Identification of such a facial involvement could have a dramatic prognostic impact. © 2013 John Wiley & Sons, Ltd.     

人工湿地植物对高盐废水中COD的去除作用

针对经生化处理的石油和精细化工工业区的工业废水盐含量较高、氮磷营养盐含量较低和COD含量较高的特点,构建了高盐度进水条件下表面流人工湿地的中试试验装置,考察了水葱、芦苇和香蒲在此类高盐废水中的生长状况,比较了三种植物混合试验单元与无植物试验单元对此类高盐废水中COD的去除效果,研究了高含盐量工业废水湿地系统内植物生长对微生物量的影响,以及植物在微生物去除COD过程中的作用。结果表明,高含盐量的工业废水对水葱、芦苇和香蒲的生长有一定的抑制作用,植物单元对工业废水中有机物的净化效果明显好于无植物单元,且植物生长越好,人工湿地内水体中的COD净化效果越好。混合植物单元对高含盐量工业废水中COD的总去除量约为无植物单元的4倍,证明植物的存在可以增强湿地单元内土壤微生物对有机物的去除能力。     

Protein and amino acid composition of the tergal gland secretions ofBlatta orientalis andEurycotis floridana (Dictyoptera: Blattidae)

Summary Nymphs and adult females ofBlatta orientalis and nymphs ofEurycotis floridana produce a proteinaceous sticky secretion which accumulates on the last abdominal tergites. The proteic patterns do not differ between individuals of the same species. HPLC analyses show that all the common amino acids are found in both species, aspartic and glutamic acids representing 24 to 37% of the total amount of amino acids. InB. orientalis, glutamic acid is the more abundant amino acid whereas inE. floridana it is the aspartic acid. The secretion appears and accumulates rapidly on isolated insects. Behavioural assays revealed that these secretions have a defensive role.     

Effects of lipids on the sorption of hydrophobic organic compounds on geosorbents: a case study using phenanthrene

The impact of the lipid fraction of natural geosorbents on the sorption of a polycyclic aromatic hydrocarbon was assessed using several experiments. In the first set of experiments phenanthrene was sorbed on a coastal sediment as well as on its humin and humic acid fractions before and after lipid extraction. Before lipid extraction, sorption shows dominantly partitioning characteristics. However, the extraction of lipids from sediment and humin drastically increases, by up to one order of magnitude, their sorption affinity for phenanthrene at low sorbate concentrations, resulting in increased isotherm nonlinearity. This effect is less pronounced for humic acids. One mechanism proposed for the increasing sorption is that lipids, despite their very low relative abundance in the sediments, can compete with phenanthrene for specific high affinity sorption sites (e.g., matrix pores and adsorption sites). This competition is not surprising considering the similar hydrophobic nature of lipids and phenanthrene. Lipids, or any non-polar molecules, could also act like plasticizers by swelling rigid domains and disrupting high affinity sites. In both cases, the removal of lipids (and extraction solvents) makes those sites available for phenanthrene. These provide alternative explanations to the previously proposed “solvent conditioning effect” believed to occur when geosorbents are treated with non-polar solvents modifying the matrix structure, an effect yet to be proven at molecular scale. To further investigate the impact of lipids on sorption, other independent experiments were performed. In a second experiment, re-addition of lipids to the extracted sediment restored the sorption isotherm linearity observed in the native material supporting the absence of irreversible extraction artifacts. However, high addition of lipids (i.e., after saturation of high affinity sites) seems to also enlarge the low affinity partitioning domain. These results are consistent with dual-mode, hole-filling, sorption models involving diffusion. In the final set of experiments, solid-state ¹⁹F-NMR using F-labeled lipids sorbed onto the sediments confirmed that lipids may be in different domains (mobile or rigid) that interact or not with phenanthrene. The possible effects of lipid removal on sorption have been overlooked and should be considered when geosorbents are pretreated.     

Atmospheric background of chlorinated hydrocarbons studied in Swedish lichens

Lichens $\text{Cladonia}$$\text{alpestris}$ collected in the northern part of Sweden were analyzed over a 10-year period for chlorinated hydrocarbons. Results show a delay of 2–3 years between the production of PCBs and the deposition of these compounds in the lichen. They confirm the low solubility of PCBs in water and the predominance of atmospheric transport of these chlorinated compounds far away from industrialized areas.     

Ecological mapping: A framework for delimiting forest management units

Ecological mapping attempts to objectively and spatially delimit and represent the natural organization and structure of the landscape. It offers nested levels of resolution, based upon a regionalization process, and provides an ecological basis for planning activities that may impact upon the environment.The essential principles of ecological mapping, as applied by the Quebec Ministry of Environment and Wildlife, are summarized. A methodological mapping approach is proposed for the determination of significant land portions for forest management using an ecological map at a scale of 1:50 000. At this scale, two nested levels of perception are expressed: 1) the topographic complex, and 2) the topographic entity. The topographic entity can be further subdivided into working units based upon operational criteria oriented to forest management. Within each nested level from topographic complex to working unit, there is a corresponding increase in the amount of detailed information available. Ecological mapping undertaken at 1:50 000 scale can provide a reliable and robust tool for planning forest management activities. In most cases, major ecological variations can be expressed and mapped at this scale; however, a greater degree of generalization must be accepted in the planning process when working at this scale rather than at larger scales.