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M J Whittle A I Wilson C R Whitfield R D Paton R W Logan 《BMJ (Clinical research ed.)》1981,282(6262):428-430
A phospholipid profile, the main features of which were the lecithin/sphingomyelin (L/S) ratio and the presence or absence of phosphatidylglycerol (PG), was determined in amniotic fluid from 188 patients. There was a mature profile (L/S ratio of at least 2 . 0 and detectable PG) in 145 patients, including seven insulin-dependent diabetics, and noe of their babies developed respiratory distress syndrome (RDS). The L/S ratio was less than 2 . 0 and PG absent in 12 patients, nine of whose babies developed RDS, whereas only three small babies (delivered between 28 and 35 weeks because of fulminant pre-eclampsia or severe abruptio placentae) out of 31 developed RDS when the L/S ratio was less than 2 . 0 but PG was present. When amniotic fluid was collected from the vagina only one out of 69 babies developed RDS when PG was present (regardless of the L/S ratio), while all of seven babies developed RDS when PG was absent. It is concluded that the amniotic fluid phospholipid profile, particularly the presence or absence of PG, gives an accurate assessment of fetal lung maturation. The profile may prove a useful adjunct to the management of high-risk pregnancies, especially after premature membrane rupture and perhaps also when the mother is diabetic. 相似文献
423.
Observations on the diagenesis of the Lower Triassic Sudair Formation,Abu Dhabi,United Arab Emirates
Summary The Lower Triassic Sudair Formation in the United Arab Emirates (U.A.E.) ranges in thickness from 178–297 m and comprises
three units consisting of interbedded limestone, argillaceous limestone, dolomite and anhydrite. The Lower Unit contains variable
energy shallow marine, slightly argillaceous mudstones and subordinate ooliticpeloidal packstones and grainstones with minor
dolomite and anhdrite. The Middle Unit consists of argillaceous and ferroan dolomite deposited in a lagoonal to supratidal
setting. The Upper Unit comprises argillaceous mudstones and dolomites at the base grading upward into argillaceous anhydrite
deposited in a restricted shallow marine to sabkha setting. These units represent the transition from a carbonate/evaporite
shelf with significant terrestrial input to an evaporitic platform defined by an overall shallowing-upward sequence.
Diagenesis in the Sudair includes extensive leaching of grain-supported carbonates, partial to complete dolomitization, evaportie
formation, clay nucleation, fracturing/pressure solution, late cementation by coarse calcite spar and saddle dolomite, and
hematite formation. These processes have had the cumulative effect of reducing the secondary porosity. Dolomitization occurred
in two stages: an earlier progression of rhombic-sucrosic-aphanocrystalline dolomite, and a later coarse crystalline and saddle
dolomite fracture fill. 相似文献
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