Maternal serum thyroid antibodies in early pregnancy and fetal Down's syndrome

Thyroid antibodies were measured in mid-trimester antenatal serum samples from 77 pregnancies affected by fetal Down's syndrome and 385 unaffected control pregnancies. Using a haemagglutination technique, thyroglobulin antibodies were detected in 5·2 per cent of cases (4) and 2·9 per cent of controls (11), and thyroid microsomal antibodies were detected in 22 per cent (17) and 15 per cent (59), respectively. Using an enzyme-linked immunosorbent assay (ELISA) for thyroglobulin antibodies and a cut-off level of 50 KIU/1, positive results were found in 25 per cent of cases (19) and 22 per cent of controls (84). Using an ELISA for thyroid microsomal antibodies and the same cut-off level, the proportions were 52 per cent (40) and 39 per cent (149), respectively. While not statistically significant, the differences were consistent with the previously reported increased levels of thyroid antibody found in nonpregnant women who had had pregnancies associated with Down's syndrome.     

本溪市水环境承载力及指标体系

水环境承载力是近年提出的一个新概念，它是用以定量描述水资源和水污染及其有关参数的一个综合指标，其含义为：在一定的自然环境条件和特定的社会经济发展模式下，区域水环境（包括水资源和水污染）对其社会经济发展的支撑能力．水环境承载力是由水环境系统结构决定的，它体现了水环境与人类社会经济活动之间的联系．对一个城市而言，不同的社会经济发展速度规模及不同的水环境治理对策，其水环境承载力各不相同，水环境承载力是区域自然条件、区域经济发展模式（发展的方向和发展的速度）及相应的水资源与水污染防治对策的函数．水环境承载力具有客观性、变动性和可控性三个基本特点，利用水环境承载力可以评判城市水环境对其社会经济发展承载大小．为区域社会经济与水环境协调发展提供决策依据．     

新型稳定塘污水处理技术AIPS

由于资金和能源紧张,高效低耗的污水处理技术受到人们的重视。AIPS新型稳定塘是由美国Oswald教授研究开发,并有30a成功经验的污水处理技术。该技术具有低投资,低运行费用、易管理、比普通稳定塘占地少的优点。      

Prenatal exclusion of Hurler's disease by leucocyte α-L-iduronidase assay

Hurler's disease was excluded in a fetus at 23 weeks' gestation by demonstrating normal iduronidase activity in fetal leucocytes following failure of amniotic cell culture after amnic-centesis at 16 and 19 weeks' gestation. The diagnosis was confirmed in the neonate.     

The recycling cycle of materials as a design project tool

Currently, a large number of companies consider recycling of materials as an opportunity to maximize profits and to reduce the environmental impact generated by these materials after they are disposed. However, there is also a strong constraint on the use of recycled materials mainly due to the lack of technical/scientific information, which would relate their physical properties to their recycling cycle. This information should be used in the initial phase of the product design to serve as reference for the simulation of a project to point out the physical properties obtained from recycling the Projected material (Pm). Thus, it would be possible to foresee some recycling strategy to keep the good characteristics of recycled materials by encouraging their use, regardless of the product to be designed.Therefore, the Recycling Cycle of Materials (RCM) is a tool that provides scientific/technical support in the selection of materials. It uses the information related to the physical properties of the Pm as a parameter for product design after five recycling cycles. For the case study, this tool has been applied to obtain the basic material of ABS/PC blend. Subsequently, this blend was evaluated using DSC, FTIR, traction and impact methods to obtain delimiting data for the definition of the mechanical properties resulting from the application of RCM.     

环境监测质量管理与控制技术体系框架研究

为进一步规范我国的环境监测质量管理工作、系统化质量控制技术,参照国外先进的质量管理经验,结合我国环境监测体系的实际情况,搭建了我国环境监测质量管理与控制技术体系框架,在做了大量基础性研究的前提下,编写了一系列支持该体系正常运行的指导性文件.     

On-road and simulated driving: concurrent and discriminant validation

Introduction

A converging pair of studies investigated the validity of a simulator for measuring driving performance/skill.

Study 1

A concurrent validity study compared novice driver performance during an on-road driving test with their performance on a comparable simulated driving test.

Results

Results showed a reasonable degree of concordance in terms of the distribution of driving errors on-road and errors on the simulator. Moreover, there was a significant relationship between the two when driver performance was rank ordered according to errors, further establishing the relative validity of the simulator. However, specific driving errors on the two tasks were not closely related suggesting that absolute validity could not be established and that overall performance is needed to establish the level of skill.

Study 2

A discriminant validity study compared driving performance on the simulator across three groups of drivers who differ in their level of experience - a group of true beginners who had no driving experience, a group of novice drivers who had completed driver education and had a learner's permit, and a group of fully licensed, experienced drivers.

Results

The findings showed significant differences among the groups in the expected direction -- the various measures of driving errors showed that beginners performed worse than novice drivers and that experienced drivers had the fewest errors. Collectively, the results of the concurrent and discriminant validity studies support the use of the simulator as a valid measure of driving performance for research purposes.

Impact on industry

These findings support the use of a driving simulator as a valid measure of driving performance for research purposes. Future research should continue to examine validity between on-road driving performance and performance on a driving simulator and the use of simulated driving tests in the evaluation of driver education/training programs.     

Risk reduction concept to provide design criteria for Emergency Systems for onshore LNG plants

The functional safety requirement is widely applied in the process plant industry in accordance with the international standards, such as IEC and ISA. The requirement is defined as safety integrity level (SIL) based on the risk reduction concept for protection layers, from original process risk to tolerable risk level. Although the standards specify both, the Prevention System and the Emergency System, as level of protection layers, the standards specify in detail only the use of the Prevention System (i.e., Safety Instrumented System (SIS)). The safety integrity level is not commonly allocated to the Emergency System (e.g., Fire and Gas System, Emergency Shutdown System and Emergency Depressuring System). This is because the required risk reduction can be normally achieved by only the Prevention System (i.e., SIS and Pressure Safety Valve (PSV)). Further, the risk reduction level for the Emergency System is very difficult to be quantified by the actual SIL application (i.e., evaluated based on the single accident scenario, such as an accident from process control deviation), since the escalation scenarios after Loss of Containment (LOC) greatly vary depending on the plant design and equipment. Consequently, there are no clear criteria for evaluating the Emergency System design. This paper aims to provide the functional safety requirement (i.e., required risk reduction level based on IEC 61508 and 61511) as design criteria for the Emergency System.In order to provide clear criteria for the Emergency System evaluation, a risk reduction concept integrated with public’s perception of acceptable risk criteria is proposed and is applied to identify the required safety integrity level for the Emergency System design. Further, to verify the safety integrity levels for the Emergency Systems, the probabilistic model of the Emergency Systems was established considering each Emergency System (e.g., Fire and Gas System, Emergency Shutdown System and Emergency Depressuring System) relation as the Overall Emergency System. This is because the Overall Emergency System can achieve its goal by the combined action of each individual system, including inherent safe design, such as separation distance.The proposed approach applicability was verified by conducting a case study using actual onshore Liquefied Natural Gas Plant data. Further, the design criteria for Emergency Systems for LNG plants are also evaluated by sensitivity analysis.     

Prenatal diagnosis for huntington's disease: A molecular and psychological study

Two linked probes were used to determine the Huntington's disease status of the fetus conceived by a woman affected with the condition. The fetus was found to be unaffected with a certainty of 97 per cent. The ethical issues associated with presymptomatic testing were avoided since the mother presented with initial symptoms of Huntington's disease, but other psychological and ethical issues arose. The concerns of an affected woman planning a pregnancy, and the dilemmas involved in decision-making regarding prenatal diagnosis and possible selective abortion were exposed and explored with the patient and her husband.     

Prenatal ultrasound diagnosis of Apert's syndrome

A mother affected with Apert's syndrome was diagnosed by ultrasound scan at 16–17 weeks to have a fetus similarly affected. The typical features of acrocephaly and symmetrical syndactyly were seen. This is probably the first time that this condition has been diagnosed at such a gestation by ultrasound scan. The patient decided to continue the pregnancy, and intrauterine death occurred at 34 weeks. The diagnosis was confirmed by pathological examination.