清洁生产审计方案评估技术方法探讨

清洁生产审计方案评估是对已获得的清洁生产方案作出科学的，系统的和全面的评估，文章对清洁生产审计方案评估技术方法进行了探讨，提出了清洁生产审计方案评估技术方法包括方案分类评价，方案筛选和可行性分析等内容。     

Trisomic pregnancies have normal human chorionic gonadotropin bioactivity

Sera from women carrying either chromosomally normal or aneuploid fetuses in the first half of pregnancy were assayed for human chorionic gonadotropin (hCG) bioactivity in order to determine whether differences might provide the basis for a useful antenatal screen for aneuploidy. A mouse uterine weight assay was used to assess hCG bioactivity in sera from 35 patients undergoing chorionic villus sampling (12 normal pregnancies and 23 trisomic pregnancies) and in sera from 18 patients undergoing elective second-trimester abortion (12 presumed normal pregnancies, 3 trisomic pregnancies, and 3 pregnancies with neural tube defects). The hCG bioactivity to immunoactivity (B:I) ratio of normal pregnancies progressively decreased from 7.7±1.3 at 4–5 menstrual weeks, to 4.7±0.4 at 9–12 menstrual weeks, to 3.3±0.5 at 16–20 menstrual weeks. There were no significant differences in the B:I ratios between normal and aneuploid pregnancies in either the first-trimester (4.7±0.4 versus 5.2±0.3) or the second-trimester samples (3.3±0.5 versus 2.6±0.3), despite significantly greater hCG concentrations in the trisomic pregnancies. We conclude that while aneuploid pregnancies display dysfunctional regulation of hCG expression, the bioactivity of their hCG is normal and does not appear to form the basis for a useful screen for aneuploidy.     

Toxic interaction mechanism of two fluoroquinolones with serum albumin by spectroscopic and computational methods

To evaluate the toxicity of two fluoroquinolones (FQs), ciprofloxacin (CPFX), and enrofloxacin (ENFX), at the protein level, their binding modes with bovine serum albumin (BSA) were characterized by multiple spectroscopic and molecular docking methods under simulated physiological conditions. On the basis of fluorescence spectra, we concluded that both FQs greatly quenched the fluorescence intensity of BSA, which was attributed to the formation of a moderately strong complex mainly through electrostatic interactions. Besides, CPFX posed more of an affinity threat than ENFX. The molecular docking methods further illustrated that both CPFX and ENFX could bind into the subdomain IIIA of BSA and interact with Arg 508 and Lys 437, the positively charged residues in protein. Furthermore, as shown by the synchronous fluorescence, UV-Visible absorption and circular dichroism data, both CPFX and ENFX could lead to the conformational and microenvironmental changes of BSA, which may affect its physiological function.     

Prenatal screening and diagnosis of neural tube defects

This review article discusses prenatal screening and diagnosis of neural tube defects (NTD). High detection rates occur in countries operating ultrasound screening programmes because classical two-dimensional ultrasound cranial signs (lemon shaped head, banana cerebellum, ventriculomegaly) are important diagnostic clues to the presence of spina bifida. Careful evaluation of both the spine and a search for other abnormalities is warranted. Important prognostic information for spina bifida relates to the lesion level, with a “watershed” between L3 and L4 marking a very high chance of being wheelchair bound with the higher lesions. Three-dimensional ultrasound using multiplanar views can achieve diagnostic accuracy within one vertebral body in around 80% of patients. There are high rates of pregnancy termination for spina bifida in many European countries, but the use of new imagining techniques allow better prediction of outcome, and consequently a refinement of prenatal counselling. Copyright © 2009 John Wiley & Sons, Ltd.