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Summary The effect of norepinephrine on fatty acid synthesis (3H2O incorporation into fatty acids), on fatty acid oxidation to CO2 and on ketogenesis was studied in isolated hepatocytes of fed rats. After incubation with norepinephrine (50 M), lipogenesis was lower (5.7±1.1 nmoles3H2O incorporated into fatty acids/mg dry weight/30 min) than in controls (7.5±1.7; n=6, p<0.02). In contrast, (1-14C) palmitate conversion into total ketone bodies was increased to 10.9±1.8 nmoles/mg/30 min with norepinephrine, vs 8.5±1.6 in controls (p<0.05), and more (1-14C) palmitate was converted to14CO2 with norepinephrine than in controls (1.48±0.10 nmoles/mg/30 min vs 1.06±0.11, p<0.05). The inhibitory effect of norepinephrine on lipogenesis was abolished by addition of the 1-receptor blocker prazosin, but not by 2 or -blockers. The results demonstrate that the ketogenic effect of norepinephrine is coupled with an inhibitory effect on lipogenesis which may be explained by diminished activity of acetyl-CoA carboxylase, diminished formation of malonyl-CoA and decreased activity of carnitine palmitoyl transferase I. 相似文献
23.
Recent studies of galaxies approximately 2-3 Gyr after the Big Bang have revealed large, rotating disks, similar to those of galaxies today. The existence of well-ordered rotation in galaxies during this peak epoch of cosmic star formation indicates that gas accretion is likely to be the dominant mode by which galaxies grow, because major mergers of galaxies would completely disrupt the observed velocity fields. But poor spatial resolution and sensitivity have hampered this interpretation; such studies have been limited to the largest and most luminous galaxies, which may have fundamentally different modes of assembly from those of more typical galaxies (which are thought to grow into the spheroidal components at the centres of galaxies similar to the Milky Way). Here we report observations of a typical star-forming galaxy at z = 3.07, with a linear resolution of approximately 100 parsecs. We find a well-ordered compact source in which molecular gas is being converted efficiently into stars, likely to be assembling a spheroidal bulge similar to those seen in spiral galaxies at the present day. The presence of undisrupted rotation may indicate that galaxies such as the Milky Way gain much of their mass by accretion rather than major mergers. 相似文献
24.
Sasquaperla hoopa , a new genus and species of Chloroperlidae, is described from adults and preemergent nymphs collected in the Coast Range of northern California. Males are characterized by the epiproct reduced to a small, tablike structure bearing stiff hairs in a narrow band along the posterior margin. Females are similar to those of Sweltsa , but the nymphs bear several erect bristles lateral to depressed hair patches on the mesosternum. Modified keys are presented for adults and nymphs. 相似文献
25.
求取剩余油饱和度的一种实用方法 总被引:5,自引:4,他引:1
杨少春 《中国石油大学学报(自然科学版)》1998,(2)
分析了水驱油田地质、测井及开发动态特征,提出了用生产井含水率资料结合测井资料求取产层平均剩余油饱和度的方法。阐述了该方法的基本模型和计算过程,并以实例计算说明了这种方法的实际应用效果。结果表明,该方法操作简便、实用性强、计算结果可靠,且能准确反映储层的剩余油分布特征。这种方法也避免了水淹层混合液电阻率、岩电系数和水淹层电阻率求取值失真的影响。 相似文献
26.
Yokoyama S Woods SL Boyle GM Aoude LG MacGregor S Zismann V Gartside M Cust AE Haq R Harland M Taylor JC Duffy DL Holohan K Dutton-Regester K Palmer JM Bonazzi V Stark MS Symmons J Law MH Schmidt C Lanagan C O'Connor L Holland EA Schmid H Maskiell JA Jetann J Ferguson M Jenkins MA Kefford RF Giles GG Armstrong BK Aitken JF Hopper JL Whiteman DC Pharoah PD Easton DF Dunning AM Newton-Bishop JA Montgomery GW Martin NG Mann GJ Bishop DT Tsao H Trent JM Fisher DE Hayward NK Brown KM 《Nature》2011,480(7375):99-103
27.
A new species of Hesperoperla is named from northern California. The adult male and female, nymph, and egg are described and figured. Hesperoperla hoguei adds a second species to this previously monotypic genus. 相似文献
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29.
Distributional data are presented for 30 species of New Mexico Plecoptera including 8 species new to the state list. Previously, many of the included species were known from a single location in the state. A revised checklist of 46 confirmed species is presented for the state. 相似文献
30.
Bill P. Stark 《西北部美国博物学家》2011,43(1)
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The western Nearctic stonefly genus Soliperla is reviewed and six species are recognized. Soliperla sierra (Calif.) and S. tillamook (Ore.) are described as new to science and illustrations of diagnostic features are presented for all species. Males and nymphs are keyed and a phylogeny for the group is proposed. 相似文献