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571.
Deficiency of amylo-1,6–glucosidase activity was expressed in parallel in liver and skin fibroblasts from a patient with type III glycogenosis. In crude extracts of control liver and muscle, amylo-1, 6–glucosidase (M.W. 164000) was identified by immunoprecipitation; no cross-reacting material was found in the patient's liver. Assay of amylo-1,6–glucosidase activity in cultured skin fibroblasts from the affected family revealed less than 10 per cent of control value in mutant homozygous cells whereas in cells from the parents, activity was reduced to 40–60 per cent of the control value. Activity in cultured amniotic fluid cells was similar to that of control fibroblasts. In cultured amniotic fluid cells obtained during the mother's subsequent pregnancy, the normal amylo–1,6–glucosidase activity measured, predicted correctly the outcome of this pregnancy prior to the 20th week of gestation. 相似文献
572.
Preparation of TiO2-MoO3 nano-composite photo-catalyst by supercritical fluid dry method 总被引:3,自引:0,他引:3
IntroductionTiO2 iswidelyusedinmultiphasephoto catalyticreactions ,andisalsooneofthemosteffectivecatalystsinthedegradationofenvironmentalcontaminants (Hoffmann ,1995 ;Fujishima ,2 0 0 0 ) .However,asasemiconductorofwidebandgap ,itcouldonlybeactivatedbyult… 相似文献
573.
A child was tentatively diagnosed as having cystic fibrosis, based on neonatal presentation with severe gastrointestinal complications; the diagnosis was not confirmed biochemically and no tissues were available for DNA analysis. The mother presented in her subsequent pregnancy, and microvillar enzyme analysis of cell-free amniotic fluid at both 18 and 20 weeks gestation gave equivocal results. The pregnancy was terminated voluntarily because of a trend towards abnormal enzyme assay results on the second amniocentesis. Retrospectively, fetal tissues were found to be homozygous for the most common mutation of the cystic fibrosis gene (AF508), which confirmed the prenatal assessment and suggested that the first infant of the couple was probably also affected by the disease. 相似文献
574.
R. H. Lindenbaum M. Ryynänen M. Holmes-Siedle E. Puhakainen J. Jonasson J. Keenan 《黑龙江环境通报》1987,7(7):511-519
Maternal serum and amniotic fluid alpha-fetoprotein levels were studied retrospectively in a total of 58 pregnancies with trisomy 18. In those pregnancies uncomplicated by either fetal exomphalos or neural tube defect the midtrimester maternal serum alpha-fetoprotein (MSAFP) levels were markedly reduced, the median value for 38 such pregnancies being 0.6 multiples of the median (MoM). Trisomy 18 with exomphalos was associated with a higher median MSAFP, but still within the normal range: 1.1 MoM, (nine pregnancies); trisomy 18 with exomphalos and neural tube defect (NTD) was associated with grossly raised levels: median MSAFP was 4-5 MoM (three pregnancies). Amniotic fluid alpha-fetoprotein (AFAFP) levels were normal in uncomplicated trisomy 18 pregnancies: median AFAFP, for 19 pregnancies, was 1.1 MoM. Exomphalos alone, or together with neural tube defect, was associated with greatly elevated levels of AFAFP; for exomphalos alone median AFAFP was 9.59 MoM (four pregnancies), and for exomphalos with neural tube defect the median AFAFP was 23.95 Mom (three pregnancies). Screening with low and high MSAFP, routine ultrasound, and amniocentesis on all women aged 35 years or over, together might identify over 50 per cent of pregnancies with trisomy 18. 相似文献
575.
磁流体处理印染废水初探 总被引:3,自引:0,他引:3
探讨了Fe3O4磁流体在不同条件下对降低印染废水的COD和色度两个方面的影响,实验表明,当pH=11,十二烷基叔胺的量是亚铁量的0.16倍时,COD降低最多,脱色效果最好,且磁场强度在160mT左右时,磁流体沉降最快。 相似文献
576.
Estimation of critical submergence for an intake in a stratified fluid media by neuro-fuzzy approach
Most of the large surface reservoirs are stably stratified throughout most or all of the year. One means of assisting in the management is to allow for the selective withdrawal from the reservoir. The value of the intake’s submergence when the upper layer fluids begin to be drawn into the intake is known as “critical submergence”. In this study, the critical submergence for a circular intake pipe in a stratified body is investigated. Experiments were conducted on a vertically flowing downward intake pipe in a still-water reservoir. Experimental results are compared with that of the neuro-fuzzy models. 相似文献
577.
Gas transfer through surface water of streams is an effective process for the environmental quality of the aquatic ecosystem.
Several theoretical approaches have been proposed to estimate gas transfer rate. This paper is devoted to present a turbulence-based
model and to compare it with other 3 turbulence-based modeling frameworks that provide an estimation of gas-transfer coefficient
KL at the air-water interface. These models were derived for the reaeration process. In this paper, they have been verified
both for reaeration and volatilization using experimental data collected in a laboratory rectangular flume and in a circular
sewer reach. These data refer to oxygen absorption and cyclohexane volatilization, respectively. Comparison of results for
oxygen shows that the tested models exhibit an average absolute difference between their results and the experimental data
ranging from 12.5% and 25.6%. Also, the scaling analysis of the experimental data support both small-eddy based models and
the model proposed by the authors. Moreover, volatilization results show that the process is also affected by a channel shape
factor, which was, finally, quantified. 相似文献
578.
Numbers of studies in externally fertilizing fish species provide evidence for an effect of ovarian fluid on sperm motility characteristics such as duration of forward mobility, velocity or percent motile sperm cells. Yet, because of variations among females in the quality of their ovarian fluid, such effects might differ between individuals. Additionally, ovarian fluid from different females could also be expected to affect each ejaculate differently, resulting in cryptic female choice. In this study on Artic charr (Salvelnius alpinus), sperm velocity from several males was measured in the diluted ovarian fluid of several females according to a fully balanced crossing design. This design allowed us to estimate variations among females in the effect of their ovarian fluid on the velocity of sperm from different males, and to detect variations among males in the ability of their sperm to swim in ovarian fluid. Sperm velocity was estimated by computer-assisted sperm analysis. Average velocity was found to vary among females, with some females having constantly higher velocity measurements in their ovarian fluid, and among males, indicating that some males had overall faster sperm in ovarian fluid than others. Moreover, variation in sperm velocity was shown to depend on individual female-male interactions. Our results document that females vary in the effect of their ovarian fluid on sperm velocity and that their ovarian fluid may stimulate sperm velocity according to individual characteristics of males. This latter result suggests a potential mechanism for cryptic female choice.
相似文献
Davnah UrbachEmail: Phone: +41-31-6313182Fax: +41-31-6314535 |
579.
通过鼠伤寒沙门氏菌致突变试验(AMES)对江苏油田含油污水、钻井液废水、废弃钻井液的致突变性进行了研究。结果表明:在本次检测条件下,以四氢呋喃做溶剂,江苏油田含油污水、钻井液废水及废弃钻井液均具有直接及间接碱基置换致突变性。 相似文献
580.
废弃钻井液的治理与利用 总被引:3,自引:1,他引:3
石油勘探开发过程中产生的废弃钻井液中含有的地层钻屑、钻井液处理剂等有害物质,若直接排放将对环境与生态造成极大的危害,其治理与利用是当前急需解决的研究课题。从1991年开始,在室内反复模拟实验研究的基础上,经过井场应用实践,研制成功了将废弃钻井液转化成水泥浆的固化技术。 相似文献