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981.
Human chorionic gonadotrophin (hCG) is the most discriminatory maternal serum marker of Down's syndrome. We have carried out a study to establish whether urinary β-core-hCG, a major metabolic product of hCG, might be an even better marker. Urine samples were available from seven singleton pregnancies with Down's syndrome, and one each of Edwards' syndrome, triploidy, and twins discordant for Down's syndrome. β-Core-hCG levels were corrected for creatinine and expressed as multiples of the normal gestation-specific median (MOM) level derived from 67 singleton controls. There was a highly statistically significant elevation in level among the singleton Down's syndrome cases (P<0·0005; Wilcoxon rank sum test). All had levels exceeding 2 MOM with a median of 6·11 MOM (95 per cent confidence interval 3·7–10·0). The levels were extremely low in Edwards' syndrome (0·08 MOM) and triploidy (0·02 MOM), but the twin pregnancy discordant for Down's syndrome did not have a raised β-core-hCG level (0·64 MOM). The findings are sufficiently encouraging to investigate the possibility of urinalysis as a routine modality in the prenatal screening for Down's syndrome and other common serious aneuploidies. 相似文献
982.
983.
Hirokatsu Akagi Koichi Haraguchi Yoshihide Kinjo Olaf Malm Fernando J. P. Branches Jeans R. J. Guimaraes 《环境科学学报(英文版)》2000,(Z1)
IntroductionSincetheearly 1980’s,rapidincreasesingoldminingactivitiesusingmercuryamalgamationtechniqueinmanydevelopingcountrieshasbeenoneofthemainsourcesofmercurypollution ,particularlyintheAmazonandothertropicalregions(Malm ,1990 ;Ramel,1996;Ikingura,1996;Lacerda,… 相似文献
984.
985.
986.
论自创生的环境法律系统 总被引:1,自引:0,他引:1
法律是自我关联的自创生系统,并且法律的发展也是法律与外界系统以及社会及其他社会子系统之间的共同进化。自创生法律系统为环境法律体系提供了一个可行的理论支持,现实中,环境法律系统对自己的现实建构来源于他自身的基本循环法律理念的法律学说、体现在保留、克服、增益、前进的自创生法律过程与循环型的法律秩序、完成于法律行为与法律规范构建。 相似文献
987.
Professor Umberto Nicolini Alessandra Kustermann Beatrice Tassis Roberto Fogliani Andrea Galimberti Elena Percivalle Maria Grazia Revello Giuseppe Gerna 《黑龙江环境通报》1994,14(10):903-906
Fifteen fetuses at risk of congenital human cytomegalovirus (HCMV) infection underwent prenatal diagnosis at 16–30 weeks' gestation by a combination of amniocentesis and fetal blood sampling. HCMV was isolated from the amniotic fluid in six patients, but HCMV-specific IgM was detected in only three of them. Two of the nine neonates, who were delivered following a negative prenatal diagnosis, had congenital HCMV infection diagnosed by virus isolation in the urine. The interval from infection to prenatal testing was 3 and 4 weeks in the two false-negative cases and ⩾ 7 weeks in the true-positive cases. Although timely testing for HCMV infection allows the option of termination of pregnancy, it may be flawed by false-negative results. 相似文献
988.
During land transformation process in the human history,naturalized plants were introduced to several land use patterns by the different ways of plant itself .Including some naturalized plants that had been contribute to land restoration,many naturalized plants have been invaded to original habitat or landscape for native plants.Once the plants were colonized,they extend their area and population size.Urban developed areas often give an impotant role of source habitat for naturalized plants and expanding their popuation size.In recent,this tituation is appearing as one of environmental problems about the urban landscape management controlling the naturalized plants that invaded in the developed area and conserving the native vegetation.This paper is focusing on relationships between distribution of habitat of naturalized plants and landscape patch in urban area in Seoul.Gengdong-Gu ,one of the administrative areas in Seoul was selected for this study.We examined the recent land use change using LANDSAT TM data and spreading of the representative naturalized plants(Robinia pseudoacacia and Eupatorium rugosum)by Seoul Biotope Mapping Project and field survey in 1999.As a result,these two species were often occurred in the same habitat and distributed in forest edge disturbed by man.Their distribution patterns were related to landscape indices (patch size and shape)in the forest edge. 相似文献
989.
Unconjugated oestriol (uE3) and human chorionic gonadotropin (hCG) levels were determined in second-trimester maternal serum (MS) samples from 21 pregnancies associated with fetal anencephaly and 15 pregnancies associated with fetal open spina bifida. Each measurement was expressed as a multiple of the median (MoM) for unaffected pregnancies for each completed week of gestation. In pregnancies associated with anencephaly, the median value for MSuE3 was very low (0–17 MoM, range <0·12–0·33 MoM), suggesting a functional defect in the fetal adrenal prior to 20 weeks' gestation; the median value for MShCG was also low (0–73 MoM), although not to the same extent as for MSuE3. A biological explanation for the hCG result is not apparent. In pregnancies associated with open spina bifida, the MSuE3 and MShCG values were unremarkable, consistent with a lack of involvement of these open fetal defects in the synthesis and secretion of uE3 and hCG. 相似文献
990.
Striving for efficiency,harmony and vitality─A human ecological approach to urban sustainable develo
Wang Rusong 《环境科学学报(英文版)》1994,(2)
Strivingforefficiency,harmonyandvitality─AhumanecologicalapproachtourbansustainabledevelopmentWangRusong(ResearchCenterforEco... 相似文献