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51.
IntroductionBothmethomylandthiodicarbareNmethylcarbmatepesticides.Methomyliseffectiveonawiderangeofinsectsasanovicide,larvicid... 相似文献
52.
IntroductionAsanewbranchofecologyandaninterdisciplinaryfield,theecologicalengineeringwasinitiallyformulatedintheearly1960s.Durin... 相似文献
53.
Maternal serum inhibin levels were measured in 19 second-trimester pregnancies affected by fetal Down's syndrome and 95 unaffected control pregnancies matched for gestational age. A statistically significant elevation was found in the affected pregnancies compared with the controls (Wilcoxon rank sum test: one-tail P=0·02). The median level in the cases was 1·3 times that in the controls, with 95 per cent confidence limits of 0·9–1·9. Although the inhibin levels were unrelated to those of alpha-fetoprotein and unconjugated oestriol in the same samples, there was a statistically significant correlation with human chorionic gonadotropin. This together with the relatively small elevation in cases suggests that inhibin would be of limited value in maternal serum screening for Down's syndrome. 相似文献
54.
G. A. Hackett Dr. J. H. Smith M. T. Rebello C. T. H. Gray D. E. Rooney R. W. Beard F. E. Loeffler D. V. Coleman 《黑龙江环境通报》1991,11(5):311-315
Early arnniocentesis between 11 and 14 weeks' gestation was offered to 110 women at risk of a chromosomally abnormal fetus due to maternal age. Four were found to be unsuitable for the procedure, and 106 early amniocenteses were performed. In 102 cases, clear amniotic fluid was obtained with a single tap. There were two dry taps and two bloodstained tapis; sampling was repeated in three of these cases before 15 weeks. In the fourth case, placental biopsy was performed at 16 weeks. Thus, we were able to obtain a satisfactory sample in all but three cases(2.8 percent). Karyotyping of cells harvested from the early amniotic fluid samples was successful in all the 105 cases. Cell culture from the initial samples revealed a normal karyotype in 99 cases, two balanced translocations, two tetraploid karyotypes, and two cases of pseudomosaicism. Of the 105 pregnancies successfully sampled, there have been two losses to date (1–8 per cent). Two further patients presented with premature rupture of membranes, both pregnancies having successful outcomes. Sixty-two babies have delivered to date, with four congenital anomalies. There were no respiratory problems. Twenty-nine pregnancies are continuing without known complications, and details are not yet available on the remaining 12. The results indicate that early arnniocentesis may replace the traditional test at 15–17 weeks. 相似文献
55.
A case of mosaic 46,XY/47,X,i(Xq)Y is diagnosed at 18 gestational weeks in amniotic fluid cells and confirmed at birth in the lymphocytes of the child. The literature on Klinefelter's syndromes with structural chromosome X rearrangements is reviewed. This is the first case reported of a mosaic isochromosome Xq in a boy. 相似文献
56.
Kang Demeng 《环境科学学报(英文版)》1995,7(3):368-373
AnevaluationofqualityassurancetomonitoracidprecipitationbyusingionbalanceinGuizhou,ChinaKangDemeng(ResearchCenterforEco-Envir... 相似文献
57.
Dr. Yash P. Agrawal Päivi Ylikangas Markku T. Parviainen Ilkka M. Penttilä 《黑龙江环境通报》1994,14(12):1141-1149
The histochemical measurement of urea-resistant alkaline phosphatase from maternal blood neutrophils is known to have a high detection rate for the prenatal detection of Down's syndrome pregnancies. However, because the histochemical method is laborious and subjective to use, it has not gained widespread acceptance in prenatal screening programmes. We present a simple and objective method for the measurement of urea-resistant alkaline phosphatase by flow cytometry. The method should allow the design of larger studies aimed at evaluating the role of neutrophil urea-resistant alkaline phosphatase in the prenatal screening for Down's syndrome. 相似文献
58.
Information on maternal age and maternal serum alpha-fetoprotein, unconjugated oestriol (uE3), and human chorionic gonadotrophin (hCG) levels was used to investigate retrospectively the effect of estimating Edward's syndrome risk in women having multi-marker screening for Down's syndrome. The screened population comprised 15 pregnancies affected by Edward's syndrome, 15 with Down's syndrome and 5472 unaffected pregnancies. The use of all three markers to estimate Edward's syndrome risk would have led to the detection of 10–12 (67–80 per cent) cases with a false-positive rate of 0.3–0.6 per cent depending on the risk cut-off. A further case would have been detected as a result of screening for Down's syndrome alone. Similar results were obtained when the Edward's syndrome risk was based on uE3 and hCG only. These data suggest that extending Down's syndrome screening to include Edward's syndrome risk will yield a high detection rate with only a small increase in the false-positive rate. 相似文献
59.
腹泻性贝类毒素的分析方法研究 总被引:11,自引:0,他引:11
本文描述了腹泻性贝类毒素的的特性,给出了已知的9种毒物成分的化学结构式衣不同毒物成分的毒性大小及毒理效应,对已有的该毒素的定量分析方法,包括生物分析法和化学分析法进行了剖析,重点阐述了化学分析法中的高效液相色谱分析法,介绍了法国目前使用的腹性贝毒的预警系统,并对我国该领域的研究提出了自己的建议。 相似文献
60.
一株高效苯酚降解菌的分离、鉴定及降解特性的研究 总被引:19,自引:1,他引:19
从污泥中分离到1株高效苯酚降解细菌JF-10.在以1000mg·L-1苯酚作为唯一碳源并加有0.05%酵母粉的无机盐培养基中,JF-10能在24h内将苯酚完全降解.该菌被鉴定为假单胞菌,与P.citronellolis、P.nitroreducens、P.aeruginosa亲缘关系较近,但生理生化特征又有差异.JF-10与P.citronelloli gyrB基因的序列相似性只有75%,与P.aeruginosa也只有80%.该菌在pH值4.0~9.0时对苯酚的降解达80%以上,加入一定浓度Mn2 、Cu2 、M2 、Pb2 对苯酚降解有促进作用;200mg·L-1的α-萘酚、苯胺能显著抑制苯酚降解,但甲苯对苯酚的降解无影响,苯酚可以促进邻甲酚的降解. 相似文献