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81.
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
82.
A computerized system which simultaneously acquires and quantifies several ultrasonically detected fetal activities, including gross body movements, breathing movements, and eye movements, was developed in order to obtain additional quantitative data on fetal behaviour. Movements were automatically related to fetal heart rate allowing computation of their mean incidence, duration, lag time and percentage time spent moving during different heart rate patterns. The incidence of various behavioural states was also calculated. The study of 15 healthy fetuses near term revealed the existence of statistically significant differences in these parameters between low and high variability patterns of fetal heart rate suggesting a quantitative modulation of fetal movements by behavioural states. 相似文献
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Over the past few years, a great deal of interest has been focused on the use of remote sensing for resource management. This paper examines one of the most useful systems — Landsat. Included in this paper is a discussion of this remote-sensing technology, its application and its future as a tool for resources planning and management. 相似文献
87.
Effects of copper and cadmium on osmoregulation and oxygen consumption in two species of estuarine crabs 总被引:2,自引:0,他引:2
Green crabs (Carcinus maenas) and rock crabs (Cancer irroratus) were exposed to various concentrations of copper as cupric chloride (CuCl2 · 2 H2O), and cadmium as cadmium chloride (CdCl2 · 21/2 H2O) for 48 h. The exposures were conducted at 5 different salinities. At the end of each exposure period, tests of blood-serum osmolality and gill-tissue oxygen consumption were performed. Copper-exposed crabs exhibited loss of osmoregulatory function with increasing copper concentration until normally hyperosmotic serum became isosmotic with the surrounding medium. Cadmium elevated greencrab serum above its normal hyperosmotic state. Copper had no effect on gill-tissue oxygen consumption; however, cadmium reduced the rate of oxygen consumption in both species tested. 相似文献
88.
Dr. D. Passia 《Marine Biology》1973,23(3):197-204
Activity of NADP+-dependent isocitrate dehydrogenase (ICDH) of the white dorsal muscle of Idus idus L. was determined by special analysis, under optimum homogenisation, centrifugation and cuvette conditions. The experimental conditions differed considerably from those used for the investigation of NADP+-ICDH activity in mammals by Bücher et al. (1964). Daily measurements of activity over a period of 10 days revealed variations in enzyme activity which are difficult to explain. However, the variations are smaller than those established in earlier tests. In order to obtain statistically valid results, the highest possible number of test fishes (at least 10 individuals for each measurement) must be investigated over a period of 5 to 10 days. NADP+-ICDH of individuals acclimated to 10°C showed 28% higher specific and non-specific activity than that of fish maintained at 20°C (experimental temperature 25°C). At 5 different adaptation temperatures, increasing activities were observed with decreasing adaptation temperature (compensation). These measurements were made over a period of 5 successive days. 相似文献
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Dr. Lon D. Drake 《Environmental geochemistry and health》1983,5(1):15-19
In the last three years, twelve orphan coal surface mines in Iowa, USA, have been reclaimed under the Federal Rural Abandoned Mine Program (RAMP) by smoothing highly acid spoils, covering the spoils with a thin dirt layer and planting a cover crop. Ten years ago a test plot was designed with a wedge of loess over acid spoils. Subsequent observation suggests that on the new RAMP sites, acidified throughflow and discharge of shallow soil moisture and groundwater will gradually kill the vegetation in the lower valleys and erosion will proceed upvalley as a migrating knickpoint. The problem might be eliminated by directing the acidified throughflow beneath the cover material, in sand underdrains or tile lines in the main drainages. The discharge could either be diluted in a nearby creek, if adequate flow is available, or neutralised in a basin paved with limestone rip-rap. Vegetation which was found to be especially well adapted to thin cover sites includes native prairie grasses, crownvetch and cattails. Sphagnum mosses may also offer some possibilities for such locations. A RAMP reclamation site should be designed as an experimental area to test these methods and determine their cost. These recommendations may also be applicable in other mining areas. 相似文献