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11.
C A Cosola-Smith L H Appell S E Abdelgadir F Stormshak 《Journal of animal science》1990,68(8):2465-2470
Experiments were conducted to examine the in vitro effects of a phorbol ester and a calcium ionophore on bovine luteal oxytocin (OT) secretion and synthesis and progesterone secretion. Corpora lutea removed from beef heifers on d 8 of an estrous cycle were sliced and incubated for 2 h with .81 nM 12-O-tetradecanoylphorbol-13-acetate (TPA), 1.62 nM TPA or .3 microM calcium ionophore A23187. Both concentrations of TPA increased (P less than .01) OT secretion (ng.g-1.2 h-1; control, 407.1; .81 nM TPA, 494.7; 1.62 nM TPA, 528.1; SE = 21.2). Increased secretion of OT was accompanied by a corresponding increase (P less than .02) in synthesis of the hormone (ng.g-1.2 h-1; control, 368.5; .81 nM TPA, 427.6; 1.62 nM TPA, 492.1; SE = 25.7). Phorbol ester also induced (P less than .025) progesterone secretion (ng.g-1.2 h-1; control, 1,056.2 vs .81 nM TPA, 1,333.3; SE = 86.4). Calcium ionophore increased (P less than .01) OT secretion (ng.g-1.2 h-1; control, 248.9 vs A23187, 327.4; SE = 16) and there was a trend (P = .09) toward increased synthesis of OT in response to the ionophore (control, 124.4 vs A23187, 165.6; SE = 16.4). Because TPA can activate protein kinase C and A23187 increases intracellular calcium, these intracellular constituents probably are involved in promoting secretion of OT and progesterone. 相似文献
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13.
K. LUND-HÖIE 《Weed Research》1969,9(2):142-147
Summary. Uptake, distribution and fate simazine (2-chioro-4,6-biserthylamino- s -triazine) in 4-year-old seedlings of Norway spruce ( Picea abies ) are discussed. Simazine was found to be readily absorbed and distributed in the spruce seedlings. A positive relationship between the amount of simazine absorbed and the growth intensities of the plants indicates an active mechanism of uptake. A fixation of simazine in roots and sterm was observed.
Simazine was degraded by roots and stem to hydroxysimazine and two other unknown metabolites. No simazine and only metabolites could be traced in the needles, indicating a very rapid rate of metabolism in the root system. The glucose derivative of benzoxazinone was extracted from all parts of the spruce seedlings and is probably responsible for the hydrolysis of simazine.
The results indicate a very slow degradation of the metabolites to CO2 as one of the final products. 相似文献
Simazine was degraded by roots and stem to hydroxysimazine and two other unknown metabolites. No simazine and only metabolites could be traced in the needles, indicating a very rapid rate of metabolism in the root system. The glucose derivative of benzoxazinone was extracted from all parts of the spruce seedlings and is probably responsible for the hydrolysis of simazine.
The results indicate a very slow degradation of the metabolites to CO
14.
K. LUND-HÖIE 《Weed Research》1969,9(3):185-191
Summary. A method of exposing seedlings of Norway spruce (Picea abies (L.) Karst.) to 14 CO2 is described. Within the 1st hr alter 14 CO2 exposure, no translocation of the 14 C out of the treated branch could be observed. After a 24-hr period, however, the 14 C in dormant seedlings had been translocated basipetally to part of the root system only, with no lateral diffusion of the 14 C-compounds in the stem. About a week after exposure, both symplastic and apoplastic patterns of translocation had caused a more uniform distribution of 14 C. In seedlings at active internode elongation, the translocation patterns were fundamentally identical to those in dormant seedlings, but the active shoot growth had led to a more uniform distribution of the 14 C.
Simazine at 20 ppm had apparently stimulated both the photofixation of14 CO2 and the rate of translocation of the 14 C-assimilates. At 30 ppm, however, simazine had blocked the translocation of nutrients to the roots. On the other hand, the 14 CO2 uptake was not influenced. The simazine incubation had apparently no influence on the synthesis of cationic photosynthate. 相似文献
Simazine at 20 ppm had apparently stimulated both the photofixation of
15.
E Dovolou IE Messinis E Periquesta K Dafopoulos A Gutierrez‐Adan GS Amiridis 《Reproduction in domestic animals》2014,49(4):665-672
Ghrelin, apart from its metabolic role, is nowadays considered as a basic regulator of reproductive functions of mammals, acting at central and gonadal levels. Here, we investigated for possible direct actions of ghrelin on in vitro maturation of bovine oocytes and for its effects on blastocyst yield and quality. In experiment 1, cumulus oocyte complexes (COCs) were matured in the presence of four different concentrations of ghrelin (0, 200, 800 and 2000 pg/ml). In vitro fertilization and embryo culture were carried out in the absence of ghrelin, and blastocyst formation rates were examined on days 7, 8 and 9. In experiment 2, only the 800 pg/ml dose of ghrelin was used. Four groups of COCs were matured for 18 or 24 h (C18, Ghr18, C24 and Ghr24), and subsequently, they were examined for oocyte nuclear maturation and cumulus layer expansion; blastocysts were produced as in experiment 1. The relative mRNA abundance of various genes related to metabolism, oxidation, developmental competence and apoptosis was examined in snap‐frozen cumulus cells, oocytes and day‐7 blastocysts. In experiment 1, ghrelin significantly suppressed blastocyst formation rates. In experiment 2, more ghrelin‐treated oocytes matured for 18 h reached MII compared with controls, while no difference was observed when maturation lasted for 24 h. At 18 and 24 h, the cumulus layer was more expanded in ghrelin‐treated COCs than in the controls. The blastocyst formation rate was higher in Ghr18 (27.7 ± 2.4%) compared with Ghr24 (17.5 ± 2.4%). Differences were detected in various genes’ expression, indicating that in the presence of ghrelin, incubation of COCs for 24 h caused over‐maturation (induced ageing) of oocytes, but formed blastocysts had a higher hatching rate compared with the controls. We infer that ghrelin exerts a specific and direct role on the oocyte, accelerating its maturational process. 相似文献
16.
Hafiz A. Abdelgadir Manoj G. Kulkarni Adeyemi O. Aremu Johannes Van Staden 《植物养料与土壤学杂志》2013,176(5):743-747
This greenhouse study tested the effect of smoke‐water and the smoke‐isolated biologically active compound karrikinolide (KAR1) on growth and photosynthetic pigments of Jatropha curcas L. seedlings. Fifteen‐day‐old seedlings were sprayed once weekly for 5 weeks with three dilutions of smoke‐water (1 : 250, 1 : 500, and 1 : 1000 v/v) or KAR1 (10–7, 10–8, and 10–9 M). Growth parameters and photosynthetic pigment concentrations of 75‐d‐old seedlings were measured. Foliar application of both smoke‐water and KAR1 on J. curcas seedlings showed significant increases in stem width, shoot length, chlorophyll a, chlorophyll b, total chlorophyll, and total carotenoid concentrations compared to the untreated control. KAR1 significantly improved leaf area, shoot and root dry mass, seedling‐vigor index, and photosynthetic pigments as compared to control treatments. These results suggest the possible use of smoke‐water and KAR1 to achieve a vigorous and well established crop of J. curcas. 相似文献
17.
Copper-Catalyzed Oxidation of Alcohols to Aldehydes and Ketones: An Efficient, Aerobic Alternative 总被引:1,自引:0,他引:1
An efficient, copper-based catalyst has been discovered that oxidizes a wide range of alcohols into aldehydes and ketones under mild conditions. This catalytic system utilizes oxygen or air as the ultimate, stoichiometric oxidant, producing water as the only by-product. 相似文献
18.
针对传统温室监控系统存在的种种弊端,设计了以单片机为前端控制器、PC机为远程监控机的上下位机控制的温室监控系统,并阐述了系统软、硬件组成,工作原理和系统实现的主要技术。 相似文献
19.
Atlantic salmon fry were reared on a fishmeal based diet with increasing levels of vitamin A (VA) (6, 122 and 938 mg retinol kg–1 dry feed) from startfeeding and for 14 weeks. Signs of VA stress, such as reduced fat stores, liver size and growth, were found for groups receiving 122 and 938 mg retinol kg–1. Signs of vitamin A toxicity, such as increased mortality, abnormal vertebral growth, and reduced growth, were found for groups receiving 938 mg retinol kg–1. These results suggest that excess VA in the early life stages of Atlantic salmon is deleterious for normal development. 相似文献
20.
Durant SM Pettorelli N Bashir S Woodroffe R Wacher T De Ornellas P Ransom C Abáigar T Abdelgadir M El Alqamy H Beddiaf M Belbachir F Belbachir-Bazi A Berbash AA Beudels-Jamar R Boitani L Breitenmoser C Cano M Chardonnet P Collen B Cornforth WA Cuzin F Gerngross P Haddane B Hadjeloum M Jacobson A Jebali A Lamarque F Mallon D Minkowski K Monfort S Ndoassal B Newby J Ngakoutou BE Niagate B Purchase G Samaïla S Samna AK Sillero-Zubiri C Soultan AE Stanley Price MR Baillie JE 《Science (New York, N.Y.)》2012,336(6087):1379-1380