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671.
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Marcel S. F Lie Ken Jie Jamal Mustafa Mohammed Khysar Pasha 《Chemistry and physics of lipids》1999,100(1-2):165-170
Five fatty ester derivatives of podophyllotoxin have been prepared by reacting the corresponding fatty acids with the hydroxy group of podophyllotoxin in the presence of dimethylaminopyridine and N,N-dicyclohexylcarbodiimide. The fatty acids incorporated are: 9,12-epoxy-9,11-octadecadienoic acid, octadec-11E-en-9-ynoic acid, 11,12-E-epoxy-octadec-9-ynoic acid, octadeca-9Z,11E-dienoic acid and 9,10-dibromooctadecanoic acid. The average yield of esterification was >95% and the structures of the products were confirmed by a combination of nuclear magnetic resonance spectroscopic and mass spectrometric analyses. 相似文献
673.
de Andrade Maíra Caetano Ugaya Cássia Maria Lie de Almeida Neto José Adolfo Rodrigues Luciano Brito 《The International Journal of Life Cycle Assessment》2021,26(5):879-898
The International Journal of Life Cycle Assessment - Fate factors, for freshwater eutrophication, represent the route of a limiting-nutrient, phosphorus or nitrogen, and their degradation in the... 相似文献
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Total serum haemolytic complement (HC) activity has been determined in 130 young bulls of the Norwegian Red Cattle Breed (NRF). A highly significant sire effect (p less than 0.01) on HC with a corresponding heritability of about 0.75 was estimated. Evidence of any simple mode of inheritance is not produced but the distribution patterns of HC indicate influences of relatively few genes. 相似文献
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In an experimental design with two matched groups (n = 13 and n = 17) working 2 and 4 hr respectively, followed by a 15-min restitution time, the study examined the effect of continuous VDT work on 1) visual acuity, refraction and oculomotor functions (ZCSV: zone of clear, single vision) and 2) the effect of 15-min restitution time on the oculomotor functions (ZCSV). In both groups there were a significant reduction in visual acuity, refraction changes in myopic direction and reduced ciliar and vergence muscle capacity. The ZCSV changes were temporary and a 15-min restitution period restored approximately half of the ZCSV changes. There were no significant differences between 2 or 4 hr of VDT work on any of the variables examined. 相似文献
679.
Kisspeptin, encoded by Kiss1, plays a key role in pubertal maturation and reproduction as a positive upstream regulator of the hypothalamic-pituitary-gonadal (HPG) axis. To examine the role of high-fat diet (HFD) on puberty onset, estrous cycle regularity, and kisspeptin expression, female rats were exposed to HFD in distinct postnatal periods. Three groups of rats were exposed to HFD containing 60% energy from fat during the pre-weaning period (postnatal day (PND) 1–16, HFD PND 1–16), post-weaning period (HFD PND 21–34), or during both periods (HFD PND 1–34). Puberty onset, evaluated by vaginal opening, was monitored on days 30–34. Leptin, estradiol (E2), Kiss1 mRNA levels, and number of kisspeptin-immunoreactive cells in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) were measured at day 34. Body weight increased only in rats exposed to HFD during post-weaning period, whereas the timing of vaginal opening was unaffected in all three groups. Leptin, Kiss1 mRNA levels, and number of kisspeptin-immunoreactive cells at day 34 were not affected by HFD. Additionally, the estrous cycle regularity was monitored in rats exposed to HFD for 40 days from weaning. Leptin, E2, and Kiss1 mRNA levels in the AVPV and ARC were measured after the HFD exposure. Thirty-three percent of rats exposed to HFD exhibited irregular estrous cycles and a two-fold increase in leptin. By contrast, E2 level and Kiss1 mRNA levels were not affected by the treatment. These data show that postnatal HFD exposure induced irregular estrous cycles, but had no effect on puberty onset or kisspeptin. 相似文献