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991.
Methods for cDNA cloning and sequencing tobacco mosaic virus RNA 总被引:2,自引:0,他引:2
992.
W.F. Williams G.S. Lewis W.W. Thatcher C.S. Underwood 《Prostaglandins & other lipid mediators》1983,25(6):891-899
On day 17 postestrus or postmating, heifers were given intrauterine injections of saline (2 pregnant, 2 non-pregnant) or 200 μg PGF2α (7 pregnant, 6 nonpregnant) through cannulae installed surgically into the uterine horn ipsilateral to the corpus luteum bearing ovary. Jugular blood samples were collected prior to the laparotomy at which the cannulae were installed during surgery, and for 90 min following the intrauterine injection. Plasma was assayed for progesterone and 13,14-dihyro-15-keto-PGF2α )PGFM). Laparotomies were reopened to confirm proper cannula placement and to determine if blastocysts were present in mated heifers. Concentrations of PGFM were higher in pregnant compared to nonpregnant heifers during the presurgery (68
26
24
26 pg/ml; P < 0.25) and surgery (186
47
65
17 pg/ml; P < .05) periods. Pregnancy status did not alter the mean concentrations of PGFM (pregnant, 554
70 pg/ml; nonpregnant, 422
81 pg/ml) or the half-life of its decline in concentration (18 min) following intrauterine injection of PGF2α. Pregnancy at 17 days in cattle does not appear to influence PGF2α transport from the uterine lumen or its metabolism in the uterus or elsewhere in response to an acute intrauterine injection. 相似文献
993.
Carol A. Hirshman Michael Darnell Thomas Brugman James Peters 《Prostaglandins & other lipid mediators》1983,25(4):481-490
Leukotriene D4 (5 μg/ml) aerosol constricts airways of dogs with nonspecific airway hyperreactivity but not of mongrel dogs which lack nonspecific airway hyperreactivity. RL increased 200 + 25% and Cdyn decreased to 77 ± 5% of the pre-challenge value. LTD4 (10 μg/ml) produced no further increase. Atropine (0.2 mg/kg) prevented the increase in RL and decrease in Cdyn, suggesting that part of the effect of LTD4 on airways is neurally mediated. 相似文献
994.
Marc J.N.C. Keirse Michel Thiery Walter Parewijck Murray D. Mitchell 《Prostaglandins & other lipid mediators》1983,25(5):671-682
Concentrations of 13, 14-dihydro-15-keto-PGF2α (PGFM) were measured in plasma of six carefully selected primigravid women with an unripe cervix at term before and at various intervals after extra-amniotic insertion of a Foley catheter with or without methylhydroxyethylcellulose (TyloseR) gel. The procedure caused an acute elevation of PGFM levels within 5 min (P < 0.025), which was maintained for at least 6 hours in the absence of uterine activation at 179 ± 32% of the initial values (P < 0.01). Extra-amniotic administration of Tylose gel caused an increase in PGFM levels which was both higher and more prolonged ( > 12 hours) than insertion of a Foley catheter alone.The observations indicate that cervical ripening without concomitant uterine activation is associated with an increase in PGFM levels. They also demonstrate that prolonged activation of (intra)uterine prostaglandin synthesis may occur several hours before the onset of labor-like uterine activity. A chance finding further suggests that spontaneous rupture of the membranes too may be preceeded by an increase in (intra)uterine prostaglandin synthesis. In their totality these observations lend strong support to the proposition that an increase in (intra)uterine prostaglandin production is a prerequisite to rather than a consequence of the initiation of labor. 相似文献
995.
996.
Cuttings of Cotinus coggyria cv Royal Purple rooted well in the spring but not at all later in the season. Levels of free and conjugated IAA and ABA were measured in cuttings taken at different times of the year. Hormones were measured in the leaf, the upper stem and the lower stem (rooting zone). In cuttings taken in early June the level of IAA was much higher than that of conjugated IAA. In late July the opposite was found. No significant differences in ABA levels were found although the ABA/IAA ratio changed dramatically. 相似文献
997.
革胡子鲶受精过程的扫描电镜观察 总被引:9,自引:1,他引:8
应用扫描电镜观察和描述了革胡子鲶成熟卵和精子的形态、卵壳膜的表面结构和形态、受精孔的位置和结构、精子入卵过程的程序和变化。讨论了精子入卵过程及精孔细胞在解体之后可能转变为一种能够吸引精子在精孔区聚集的“受精素”物质等问题。 相似文献
998.
Pyrethroid-treated bednet effects on mosquitoes of the Anopheles gambiae complex in The Gambia 总被引:2,自引:0,他引:2
S. W. LINDSAY J. H. ADIAMAH J. E. MILLER J. R. M. ARMSTRONG 《Medical and veterinary entomology》1991,5(4):477-483
The response of Anopheles gambiae complex mosquitoes to men sleeping under insecticide-impregnated or untreated bednets in six verandah trap huts was studied during the dry season in The Gambia. With this type of hut it was possible to collect live and dead indoor-resting mosquitoes and estimate the number of wild mosquitoes which entered, bloodfed on man, and exited each night. Bednets were treated with emulsions targetted to leave deposits of 25 mg/m2 lambda-cyhalothrin, or 5, 50 or 500 mg/m2 permethrin, diluted from emulsifiable concentrates (EC), or a blank formulation similar to the EC except that the permethrin was omitted; the sixth net was left untreated. Nets and sleepers were rotated between huts on different nights, the design being based on a series of Latin squares and conducted double-blind. Permethrin-impregnated bednets deterred mosquitoes from entering the huts. The degree of deterrency was proportional to the dosage of permethrin. This effect was also caused by the blank formulation and therefore attributed to other components of the formulation, rather than to the permethrin itself. The net impregnated with 500 mg permethrin per square metre gave the best individual protection, reducing mosquito bloodfeeding by 91% compared with untreated nets. However, lambda-cyhalothrin was proportionately more insecticidal than permethrin at doses of equivalent deterrency. At this stage of research, it remains conjectural whether chemical deterrency or killing of malaria vectors is better for community protection. 相似文献
999.
1000.
对苹果心室及霉心病病果心室的微生物区系,霉心病的发病特点及生态防治做了系统研究,认为霉心病及健康果实心室存在多种微生物,霉心病的发生是微生态系统失调引起的。霉心病具有复合侵染、潜伏侵染特性。一些芽孢杆菌(Bacillus.sp)对病原菌有拮抗作用。生态防治可以应用于霉心病的防治。 相似文献