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981.
A method for the determination of aspirin esterase activity in serum is described. Sera from 59 pregnant women who were habitual aspirin users were found to have a mean enzyme activity value statistically lower than those of 68 non-pregnant women controls or of 12 pregnant women controls who were either occasional users of the drug or were non-users. The distribution of enzyme activity in the experimental group was also significantly different from that of the control group. It is postulated that the low enzyme activity may further aggravate the injurious effects of high intake of aspirin. 相似文献
982.
V. Das Gupta 《Drug development and industrial pharmacy》1982,8(6):869-882
A stability-indicating assay method for ethacrynic acid based on high pressure liquid chromatography was developed. The method developed is sensitive, accurate and precise (standard deviation based on 6 readings was ± 1.5%). It was used to study the stability of ethacrynic acid in various aqueous systems. The stability tests were conducted at room temperature as well as at 65°, at various pH values and using different vehicles. The data were treated mathematically to estimate various K values. It has been shown that ammonium ion causes a fast reversible decomposition of ethacrynic acid. Formaldehyde appeared to be one of the products of decomposition. 相似文献
983.
Sengupta N. Gupta M.D. Reddy B. Dutta H. Sarkar S. 《Antennas and Propagation, IEEE Transactions on》1983,31(4):620-624
A comparison of the signal intensity fluctuations or scintillation of signal level, observed over two line-of-sight links is presented. These links are situated over Calcutta, DumDum-Andul (6.7 GHz) and Delhi, Delhi-Sonepat (7.6 GHz). The study reveals departures, in the occurrence and variation of the scintillation over the Calcutta path as compared with the path over Delhi. This deviation has been attributed to the large variation in humidity which exists in the coastal region, and also which plays a major role in microwave propagation in the troposphere. 相似文献
984.
Polarographic reduction of some coupled product of acetyl acetone with aryl diazonium chloride takes place in a single 4-electron transfer, giving a diffusion controlled irreversible waves in B.R. buffers of pH range 2–11.8. The reduction in these compounds takes place at the ---NH---N=C bond. Effect of various cations, anions, surfactant and solvent percentage on the reduction has been discussed. 相似文献
985.
Correlation between atmospheric radio noise-burst amplitudes measured by the Aiya noise meter with different bandwidths was examined during periods of local thunderstorm activity. The investigations were carried over a frequency range of 100 kHz to 9 MHz and over a 6-dB bandwidth range of 300 Hz to 16 kHz. The correlation observed in all cases was so high that the standard error of estimate was nearly equal to the accuracy of measurement itself. This suggests that the phenomenon is deterministic rather than statistical. The practical utility of the result is discussed. 相似文献
986.
The paper is concerned with the dispersion of a solute in a Bingham plastic fluid flowing in a pipe or a parallel plate channel. For pipe flow, the dispersion coefficient K2 first increases with ξ0 (the dimensionless radius of the plug flow region), reaches a maximum and then decreases. But in a channel flow, K2 decreases monotonically with increasing ξ0. Further K2 for channel flow is found to be larger than that for pipe flow for all values of ξ0 except 0.8≤ξ0≤1. 相似文献
987.
The following enzyme activities were demonstrated in cell-free homogenates from developing jojoba cotyledons: 1) elongation
of long chain acyl-CoAs in the presence of malonyl-CoA and NADPH (or NADH), 2) NADPH-dependent reduction of long chain acyl-CoAs
to the corresponding alcohols, 3) esterification of long chain acyl-CoAs and the alcohols produced from them into wax, 4)
elongation of stearoyl-ACP to eicosanoate and docosanoate as well as reduction to stearyl alcohol, 5) desaturation of stearoyl-ACP
to oleate in the presence of reduced ferredoxin, and 6) incorporation of malonyl-CoA into long chain fatty acids and alcohols
in the presence of added acyl carrier protein. These activities were associated entirely with the floating wax pad after centrifugation
of the cell-free homogenate at 12,000 g for 20 min. The relevance of the above reactions (1–6) to wax biosynthesis in vivo
is discussed. Production of oleate from acetate by enzymes utilizing ACP-thioesters as substrates followed by conversion of
oleyl-ACP to oleoyl-CoA (via free oleic acid) for subsequent elongation, reduction, and esterification, is presented as the
most probable in vivo pathway, for wax biosynthesis. The substrate specificities of the elongation and reduction reactions
utilizing acyl-CoAs as substrates are examined in terms of wax composition. 相似文献
988.
Precipitation in an Al-3 pct Cu age-hardening alloy has been monitored at 130°C by ultrasonic pulse-echo measurements of attenuation
and sonic velocity at 15 to 75 mHz and resonance bar damping and dynamic modulus measurements at 80 kHz. The use of two internal
friction measurement techniques allows separation of the total damping loss into its component parts. Damping and modulus
defect remain constant with time up to 100 hr, whereupon they begin to increase and reach a maximum at 250 hr. The observed
time dependence is associated with scattering losses by precipitate particles and with increasing dislocation damping as dislocations
become increasingly mobile during the depletion of their solute atmospheres by growing solute-rich precipitates. 相似文献
989.
A retrospective study of neonatal meningitis for a period of 6 years (1970 to 1975) is described. It was found that though the survival rate had increased since the introduction of the aminoglycosides, it was at the expense of major neurological sequelae in the survivors. It is suggested that breast feeding of all infants in the first few days of life will reduce the incidence of neonatatl meningitis. It is recommended that pooled human breast milk should not be heat-sterilized as this destroys anti-Escherichia coli immunoglobulin A. 相似文献
990.
A solar device has been developed for manufacturing candles from paraffin wax, utilizing solar energy. The design, operation and performance of the device have been described. It is concluded that the device can be used for saving fuel, minimizing the loss of wax due to the vaporization and labour. 相似文献