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Kaluzhnaya OV Belikov SI Schröder HC Wiens M Giovine M Krasko A Müller IM Müller WE 《Die Naturwissenschaften》2005,92(3):134-138
In a preceding study it has been reported that the freshwater sponge Lubomirskia baicalensis, living in Lake Baikal (East Siberia), is composed of spicules forming a characteristic pattern which follows radiate accretive growth. Here we report that the spicules are synthesized by the enzyme silicatein, a protein which is related to cathepsin L. The cDNAs for silicatein and the related cathepsin L were isolated and used as probes to show that the mRNA levels of silicatein in the bases of the spicule skeleton of the animals are low, while the mRNA level of cathepsin L in this region exceeds that of the growing zone. This is the first comprehensive study on the importance of the axial filament/silicatein as an essential structural and functional component determining the growth and stability of demosponge spicules.Note: Sequences from Lubomirskia baicalensis have been deposited in the EMBL/GenBank; cDNAs for the putative silicatein (LBSILICA) are deposited under the accession no. AJ786771 and for cathepsin L (LBCATL) under the accession no. AJ786770. 相似文献
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Non-invasive prenatal screening (NIPS) has revolutionized the approach to prenatal fetal aneuploidy screening. Many commercial providers now offer analyses for sub-chromosomal copy number variations (CNVs). Here, we review the use of NIPS in the context of screening for microdeletions and microduplications, issues surrounding the choice of disorders tested for, and the advantages and disadvantages associated with the inclusion of microdeletions to current NIPS. Several studies have claimed benefits; however, we suggest that microdeletions have not demonstrated a low enough false positive rate to be deemed practical or ethically acceptable, especially considering their low positive predictive values. Because a positive NIPS result should be confirmed using diagnostic techniques, and false positive rates are as high as 90% for some microdeletions, diagnostic testing seems preferable when the goal is to maximize the detection of microdeletion or microduplication syndromes. 相似文献
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E. E. C. Roelofsen L. I. Kamerbeek Tj. Tymstra J. R. Beekhuis A. Mantingh 《黑龙江环境通报》1993,13(8):741-747
We studied the opinions and experiences concerning maternal serum screening of two groups of women: (A) women who were not eligible for prenatal diagnosis; and (B) women for whom prenatal diagnosis was available because of advanced maternal age, and who either underwent chorionic villus sampling or amniocentesis. Many of the women were in favour of the availability of serum screening and would apply for this test in a future pregnancy. This applied also to many respondents who had previously undergone prenatal diagnosis. Most of these women, however, did not intend to decline diagnostic amniocentesis if the screening results did not indicate an increased risk. The majority of the group of respondents of 36 years and over did not consider it acceptable if age indication was dropped altogether. A system based on serum screening will have other implications than a policy based on age indication, since specific individual risk assessment is perceived as being of more significance than a risk statistically derived from age alone. Serum screening is often seen as a means of reassurance and many women are not aware of the possible drawbacks. As technology becomes increasingly complicated, counselling has to be adjusted correspondingly. Further research is needed to establish whether and how distress can be minimized and well-considered individual choice can be achieved. 相似文献
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Germán Arana-Landin Iñaki Heras-Saizarbitoria 《Journal of Cleaner Production》2011,19(9-10):1007-1015
A Spanish ecodesign standard (the UNE 150301) is being used as a basic reference point in paving the way for the future ISO 14006 ecodesign standard which may foreseeably be passed in 2011. This article aims to analyze the experience regarding adoption of the UNE 150301 in Spain.Following an analysis of the standard’s structure, its objectives and scope, its real implementation process is then analyzed based on an exploratory qualitative study carried out in four Spanish companies that have been pioneers in adopting this environmental standard. The conclusion is drawn in the article that in all the cases analyzed, the greatest source of impact occurs in the phase in which the product is used and is related to energy consumption. Companies appear to be satisfied with the adoption of this standard and, in particular, point out that they have managed to reduce the environmental impact of their products. However, they draw attention to the fact that, to deal with certain instances of impact that increases in cost entail, administrative bodies need to establish mandatory regulations, as environmentally-friendly companies would otherwise lose competitiveness. 相似文献