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631.
During 1988 and 1989, 3565 women booked under consultants who performed an ultrasound scan at booking, whilst 4984 booked under consultants who performed a formal mid-trimester scan between 16 and 18 weeks. All significant anomalies diagnosed prenatally and in the neonatal period were recorded, the incidence in each group being 12.9/1000 and 9.83/1000, respectively (NS). The sensitivity of diagnosis before 20 weeks was 45 per cent in the ‘mid-trimester’ group (kappa 0.62) compared with 30 per cent in the ‘booking’ group (kappa 0.46), overall sensitivity of prenatal diagnosis, however, being similar in both groups (63 vs. 65 per cent, kappa 0.77 vs. 0.79). Cardiac anomalies were the single largest group which were not detected equally prenatally in both groups. This study shows that formal mid-trimester scanning leads to anomalies being detected significantly earlier in the antenatal period. Although not statistically significant, three lethal anomalies were missed prenatally in the ‘booking’ group which we would have expected to diagnose on a mid-trimester scan. These figures are discussed in the light of previous reports. 相似文献
632.
The problems of reproduction of Octopus vulgaris and the seasonal distribution in the sea of planktonic larvae, benthonic juveniles and adults are discussed. The influence of environmental factors on growth is shown by experimental studies in the laboratory, and the difficulties of interpreting field data are emphazised.Dedicated to Professor Dr. Adolf Portmann on his 75th birthday, 27 May, 1972Laboratoire associé au C.N.R.S. 相似文献
633.
634.
O. N. Luk’yanova 《Russian Journal of Ecology》2006,37(3):205-209
The functional state of the indicator species, the Gray mussel Crenomytilus grayanus (Bivalvia), has been analyzed in five areas of Peter the Great Bay exposed to anthropogenic pollution. The following indices of the state of mussels have been used: molecular biomarkers of energy metabolism—Na+,K+-ATPase, Mg2+-ATPase, and total ATPase activity—as well as the level of lipid peroxidation (LPO) and glutathione concentration in the hepatopancreas, gills, and gonads of mussels. The activity of ATPases, LPO level, and glutathione concentration significantly change in mussels from polluted areas relative to those in mussels from a conventionally unpolluted area (a bay in the Far Eastern State Marine Reserve). The molecular biomarkers used in the study provide reliable information on animal metabolism in impact areas. With consideration of the data obtained, it is concluded that the state of mussels in polluted areas is impaired. 相似文献
635.
E. G. Plotnikova D. O. Rybkina L. N. Anan’ina O. V. Yastrebova V. A. Demakov 《Russian Journal of Ecology》2006,37(4):233-240
Microorganisms capable of degrading monocyclic and polycyclic aromatic hydrocarbons and several chlorinated aromatic compounds were isolated from soils polluted with industrial waste from chemical plants. They were identified as representatives of the genera Pseudomonas, Flavobacterium, Alcaligenes, Rhodococcus, Microbacterium, Cellulomonas, Arthrobacter, and Brevibacterium. Among them, bacteria capable of utilizing xenobiotics in a wide range of ambient temperatures and pH and in the presence of high sodium chloride concentrations were revealed. 相似文献
636.
O. Hildingson 《Environment international》1982,8(1-6)
Radon daughter levels have been monitored in 12,000 Swedish dwellings during the last two years. In 1979 the Swedish Government introduced temporary limits for the radon daughter concentration in dwellings. For existing buildings this limit is 400 Bq/m3 (0.11 WL). Two different methods were used to monitor the radon daughter concentration. The majority of the houses presented in this paper were monitored using a track-etch detector; some houses were tested using a filter sampling technique while the ventilation rate was determined. Close to 15% of the investigated houses have a radon daughter concentration higher than 400 Bq/m3. The majority of these houses were one-family houses. Almost 10% of this group has a concentration above 1000 Bq/m3 (0.27 WL). The results from this study show that the two most important sources for radon in buildings are building materials and the ground. 相似文献
637.
Pure fetal blood has been aspirated in utero from the umbilical vein near the placental insertion of the cord using a twenty gauge needle under ultrasound guidance. Sixty-six samples were taken on 63 pregnancies between 17 and 32 weeks of gestation. One to two millilitres of blood can be obtained easily without amniotic fluid dilution or contamination by maternal blood, as confirmed by the measurements of the mean corpuscular volume, the histogram distribution of the red blood cells and the hematocrit. In all cases the Kleihauer test and isoelectrofocusing of the hemoglobins were performed. Coagulation factors were also studied in 60 cases. In 17 cases a medical abortion was voluntarily induced after the procedure, and the follow-up was normal during the observation period after sampling. In the other cases, pregnancies have continued normally and twelve healthy babies have already been born. 相似文献
638.
In 1986, application of lime within the upper wetland area of sector VII of the Loch Fleet catchment initiated numerous unscheduled small-scale experiments on the vegetation of this heterogeneous terrain. Vegetation changes and erosion were monitored in permanent or relocated plots established in 1987 and 1989 and re-surveyed in 1993, seven years after liming.
The most striking early effect, possibly occurring within a few weeks of lime application, was the death of Sphagnum papillosum carpet in soakways within the 2.5 ha area. Some patches of dead material were washed away, but bare surfaces were generally colonised by vascular plants, notably Juncus bulbosus. Effects in moorland and bog communities with dwarf shurbs were more subtle, involving reduction in Sphagnum cover and expansion of Erica teralix, Molinia caerulea, sedges and Narthecium ossifragum, but little change in the frequency of occurrence of Calluna vulgaris. 相似文献
The most striking early effect, possibly occurring within a few weeks of lime application, was the death of Sphagnum papillosum carpet in soakways within the 2.5 ha area. Some patches of dead material were washed away, but bare surfaces were generally colonised by vascular plants, notably Juncus bulbosus. Effects in moorland and bog communities with dwarf shurbs were more subtle, involving reduction in Sphagnum cover and expansion of Erica teralix, Molinia caerulea, sedges and Narthecium ossifragum, but little change in the frequency of occurrence of Calluna vulgaris. 相似文献
639.
640.
V O Biederbeck 《Journal of environmental science and health. Part. B》1979,14(5):475-493
When sewage effluent was pumped from a lagoon for spray irrigation the pumping process reduced the fecal coliforms (FC) by 66% and the fecal streptococci (FS) by 91%. Bactericidal effects associated with the pumping of effluent were investigated in the laboratory by seeding sterilized effluent with fecal bacteria and repeatedly passing the liquid through a centrifugal impeller type pump at 50 psi pressure. The pumping effect was cumulative, 49 and 90% of FC being killed after two and four passages through the pump, respectively. FC were more susceptible than FS to injury by pressure shock. Very weak chlorination of the effluent increased the destruction of FC but not FS during subsequent pumping. Within the range of experimental conditions used, the percentage of FC killed by pumping was not markedly affected by changes in temperature and pH of the effluent or by differences in the number and age of cells added. 相似文献