First-trimester screening for Down syndrome; the role of nasal bone assessment in the Korean population

Objectives The aim of this study was to evaluate the role of nasal bone assessment in first-trimester screening for Down syndrome (DS) in the Korean population. Methods From July 2004 to March 2006, we prospectively evaluated the fetal nasal bones at 11–14 weeks' gestation in the Korean population. Results A successful evaluation was possible in 6490 of 6787 fetuses (95.6%). Absent, hypoechoic, and short nasal bones were seen in 4 (26.7%), 4 (26.7%), and 1 (6.7%) of 15 fetuses with DS, respectively, whereas in 5 (0.1%), 11 (0.2%), and 246 (3.8%) of 6456 normal fetuses. The incidence of absent and hypoechoic nasal bone showed significant differences between normal fetuses and fetuses with DS (P < 0.0005, both). Screening for DS using an absent or hypoechoic nasal bone resulted in a sensitivity of 53.3%, a specificity of 99.8%, a positive likelihood ratio of 215.2, and a negative likelihood ratio of 0.5. Conclusion Our study showed that nasal bone abnormality at 11–14 weeks of gestation had a high association with DS in the Korean population. This suggests that nasal bone assessment can be used to supplement the current first-trimester screening for DS in the Korean population. Copyright © 2007 John Wiley & Sons, Ltd.     

Monitoring of bacterial morphology for controlling filamentous overgrowth in an ultracompact biofilm reactor.

This research was part of a study of filamentous growth and control in an ultracompact biofilm reactor (UCBR). Morphologies of biofilm and filamentous bacteria in the UCBR were investigated. Ethanol was used as a substrate and sodium hypochlorite was applied as a toxicant to control filamentous growth. The results indicated that factors such as chemical oxygen demand, surface loading rate, pH, and dissolved oxygen could initiate filamentous overgrowth in the UCBR. Different biofilm and filamentous morphologies in the UCBR were observed under different operational conditions. Chlorination was an effective approach to control filamentous growth during and after biofilm formation. Proper chlorine dosing had no effect on biofilm, but killed filaments. Overdose of chlorine damaged biofilm and caused adverse effects such as low treatment efficiency, media clogging and washout, and biofilm color change in the reactor. Frequent monitoring of the morphologies of filaments and biofilm was needed during chlorination to prevent chlorine overdose.     

Prenatal diagnosis of pseudo arylsulphatase a deficiency

Prenatal diagnosis was performed on a pregnancy at risk for metachromatic leukodystrophy (MLD) in a family with the pseudo arylsulphatase A deficiency trait. Extracts of cultured amniotic fluid cells were deficient in arylsulphatase A indicating that the fetus was either affected with MLD or had the benign pseudodeficiency trait. In the cerebroside sulphate loading test, the at risk cells hydrolysed sulphatide like control cultured amniotic fluid cells implying that the fetus had pseudodeficiency. The pregnancy was carried to term and a male child was delivered. Placenta, urine and fibroblasts had very low activities of arysulphatase A. However, no sulphatide could be detected in urine and growing fibroblasts responded normally in the cerebroside sulphate loading test, suggesting pseudodeficiency. At 29 months, the infant is healthy and shows no stigmata of MLD. The prediction based on the results of the cerebroside sulphate loading test on cultured amniotic fluid cells appeared to be borne out.     

A global health problem caused by arsenic from natural sources

Arsenic is a carcinogen to both humans and animals. Arsenicals have been associated with cancers of the skin, lung, and bladder. Clinical manifestations of chronic arsenic poisoning include non-cancer end point of hyper- and hypo-pigmentation, keratosis, hypertension, cardiovascular diseases and diabetes. Epidemiological evidence indicates that arsenic concentration exceeding 50 microg l(-1) in the drinking water is not public health protective. The current WHO recommended guideline value for arsenic in drinking water is 10 microg l(-1), whereas many developing countries are still having a value of 50 microg l(-1). It has been estimated that tens of millions of people are at risk exposing to excessive levels of arsenic from both contaminated water and arsenic-bearing coal from natural sources. The global health implication and possible intervention strategies were also discussed in this review article.     

Biofiltration pretreatment for reverse osmosis (RO) membrane in a water reclamation system

Biofouling control is considered as a major challenge in operating membrane systems. A lab-scale RO system was setup at a local water reclamation plant to study the feasibility of using biofiltration as a pretreatment process to control the biofouling. The biological activity in the RO system (feed, product, reject streams) was tested using the standard serial dilution plating technique. Operational parameters such as differential pressure (DP) and permeate flowrate of the system were also monitored. Effects of biofilter on AOC and DOC removals were investigated. Biofiltration was found to be a viable way of assimilable organic carbon (AOC) and dissolved organic carbon (DOC) removals, with removal efficiencies of 40-49% and 35-45% at an empty bed contact time (EBCT) of 30 min. It was also found that using the biofiltration as a pretreatment reduced the rate of biofouling. It took only about 72 h for biofouling to have a significant impact on the performance of the RO membrane, when the system was operated without using biofiltration as pretreatment. There was, however, a five times increase in operational length to more than 300 h when biofiltration was used. This study presented the suitability of the biofilter as an economical and simple way of biofouling control for RO membrane.     

废塑料裂解生产原料油的研究

本文对聚乙烯和聚丙烯的混合物裂解成原料油进行了研究 ,在 44 0℃条件下 ,不同比例的聚乙烯和聚丙烯被裂解。结果发现 ,聚丙烯有最高的液体回收率。几种催化剂被应用到聚丙烯的裂解过程中。裂解产品组分的构成及催化剂的选择是本研究的主要内容。通过比较几种不同催化剂的催化结果发现 ,复合催化剂有更好的催化效果。本研究为将来的废塑料综合利用提供了一种新的有用方法     

Climate adaptation management and institutional erosion: insights from a major Canadian port

This paper performs an institutional analysis of the adaptation to climate change by ports, through a case study of the port of Vancouver, Canada. While previous literature has demonstrated the value of informal institutions for filling gaps left by formal institutions, the role of failed informal institutions has received less attention. Our analysis reveals how, in the case of an unprecedented challenge like climate adaptation, relying on informal institutions with less agency can actually erode the strength of existing institutions in a form of negative institutional plasticity. In this case, emerging polycentric governance was unsuccessful, unable to construct clearly demarcated responsibilities due to impedance by the path dependence of the current federalist system. The latter works well for traditional infrastructure investments with a closed pool of stakeholders, but not for ports where multiple scales of embeddedness, both horizontally and vertically, produce a collective action problem with no mechanism for resolution.     

Goal striving,idiosyncratic deals,and job behavior

Two important gaps remain to be filled in the idiosyncratic deals (i‐deals) literature. First, it is unclear which employees are predisposed to seek and receive i‐deals. Second, it is unclear how employees' perceptions of whether their coworkers are receiving i‐deals affect their own i‐deal experiences. This study proposed a theoretical model suggesting that (a) three key motivational goals identified in human development research, that is, achievement, status, and communion striving, predispose employees to seek and receive i‐deals; (b) employees' perceptions of whether their coworkers are receiving i‐deals moderate these relationships; and (c) employees' i‐deals are related to their job behavior. Data collected from more than 400 working adults in Italy showed that employees' motivational goals (particularly achievement and status striving) were positively related to the levels of i‐deals they received, and that these i‐deals were in turn positively related to supervisors' assessments of their in‐role job performance, voice behavior, and interpersonal citizenship behavior. High perceptions of the extent to which coworkers received i‐deals further strengthened the relationship between status striving and employees' perceptions of their own i‐deals, highlighting a trait‐situation interactionist perspective on employees' i‐deal experiences. Copyright © 2015 John Wiley & Sons, Ltd.