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排序方式: 共有89条查询结果,搜索用时 18 毫秒
1.
Heather B Bradshaw Neta Rimmerman Sherry Shu-Jung Hu Valery M Benton Jordyn M Stuart Kim Masuda Benjamin F Cravatt David K O'Dell J Michael Walker 《BMC biochemistry》2009,10(1):14-11
Background
N-arachidonoyl glycine (NAGly) is an endogenous signaling lipid with a wide variety of biological activity whose biosynthesis is poorly understood. Two primary biosynthetic pathways have been proposed. One suggests that NAGly is formed via an enzymatically regulated conjugation of arachidonic acid (AA) and glycine. The other suggests that NAGly is an oxidative metabolite of the endogenous cannabinoid, anandamide (AEA), through an alcohol dehydrogenase. Here using both in vitro and in vivo assays measuring metabolites with LC/MS/MS we test the hypothesis that both pathways are present in mammalian cells. 相似文献2.
Coastal erosion, accelerated by sea level rise, and subsidence are major Louisiana issues. With current sea-level-rise projections, coupled with the state's eroding barrier islands and coastal wetlands, the region's estuarine environments are in jeopardy of being lost, redefined, or permanently altered. As the coast erodes, Louisiana is endangered of losing valuable wetland's habitat. In addition, if the barrier islands disappear, the region's wetland-oriented oil and gas wells and associated infrastructure will be at risk to open Gulf conditions. If this should occur, each well, pipeline, and storage battery represents a potential environmental catastrophe. 相似文献
3.
This paper deals with robustness of adaptive control of continuoussystems subject to known output delay, input saturation, unmodelledlinear dynamics, and bounded disturbances. A simple gradient-typealgorithm with a relative deadzone is used. The relative deadzoneis built with an estimated contribution of the unmodelled dynamicsto the system output. The basic tool used for stability androbustness analysis is Gronwall's lemma. 相似文献
4.
MENG Jian REN Yu-Fang LI Xiao-GuangLaboratory of Rare Earth Chemistry Physics Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun Jilin ChinaPopov V.V. Repin S.M. Smirnov LA. loffe Physicotechnical Institute Russian Academy of Sciences Saint Petersburg Russia 《中国化学》1994,12(5):419-424
YBa2Cu3-xVxO7-y(x=0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) superconductors have been prepared. X-ray diffraction shows that the system remains orthorhombic for all compositions studied, but for x > 0.4 V2O5 was detected as an impurity phase. Substitution of V5+ for Cu2+ occurs in the Cu(2) sites on the Cu(2)-O planes. The introduction of the high valence element, vanadium, produces the extra free-electrons. These electrons recombine with the positive carrier of the system. It makes depression of the mobility and the Hall number of YBa2Cu3-xVxO7-v and also results in a depression of TC. 相似文献
5.
SOLIMAN A.Y. BAKEER H.M. ATTIA LA.Science Department Faculty of Teachers P.O.Box Alhasa Saudi Arabia Chemistry Department Faculty of Science Fayoum Cairo University EgyptFaculty of Engineering Ain Shames University Egypt 《中国化学》1996,14(6):532-540
3-(4-Phenyl) benzoyl propionic acid was used as the starting material for the synthesisof furanones (2), pyrrolinones (5), pyridazinones (7), benzoxazinones (8) and quinazolinones (9-11). The behaviour of the derivatives of furanones and benzoxazinones toward different nucleophiles is reported. 相似文献
6.
MARIAN ELBANOWSKI MARIA PAETZ JANUSZ SIAWINSKI LESZEK CIELA 《Photochemistry and photobiology》1988,47(3):463-466
Abstract— Chemiluminescence of the Eu(II)/Eu(III)-adenine nucleotide-H2 O2 system and fluorescence of the Eu(III)-adenosine triphosphate system have been investigated. The spectral distribution of the chemiluminescence emission has shown an occurrence of three main bands (Λ=470–480,590–620 and ca. 700 nm). The energy transfer process from the adenosine triphosphate molecules to the Eu(III) ions has been observed in the fluorescence spectrum. The examined chemiluminescence and fluorescence spectra show that these both kinds of emission originate from the 5 D *** τ7 F*** ( n =1–4) transitions in the Eu(III) ions. 相似文献
7.
电感耦合等离子体-发射光谱法(ICP-AES)快速测定饮用水中8种微量元素 总被引:4,自引:0,他引:4
用电感耦合等离子体-发射光谱法(ICP-AES)同时快速测定饮用水中微量的铜、铅、锌、铁、锰、镉、铬、砷,具有快速、简便、灵敏度高等优点,精密度为1.2%~8.2%(RSD,n=5).回收率为90%~110%. 相似文献
8.
O'Dell LA Gunawidjaja PN Holland MA Mountjoy G Pickup DM Newport RJ Smith ME 《Solid state nuclear magnetic resonance》2008,33(1-2):16-24
The HfO2-SiO2 system is attracting interest as a possible new dielectric material in semiconductor devices. Knowledge of the location of hafnium within the silica network and the effect hafnium has on the structure will be central to the successful use of this material system in this application. Here, sol-gel techniques have been used to manufacture (HfO2)x(SiO2)1-x samples (x=0.1, 0.2 and 0.4, each heat treated at 250, 500 and 750 degrees C) and these have been characterised by magic angle spinning (MAS) NMR (1H, 13C, 17 O, 29Si), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis. 29Si MAS NMR showed that increasing the hafnia content decreases the connectivity of the silicate network, i.e. increases the range of differently connected SiO4 (Qn) units with more having increased numbers of non-bridging oxygens (i.e. lower n). FTIR and 17 O MAS NMR showed unequivocally that the x=0.4 sample phase-separated at higher temperatures, while in the x=0.1 sample the hafnium was homogeneously mixed into the SiO2 phase without any phase separation. 相似文献
9.
Interaction of hydrazine or dimethylhydrazine with 5-diazoimidazole-4-carboxamide produced, presumably via tetrazenes, high yields of 5-azidoimidazole-4-carboxamide. In contrast, when semicarbazide reacted with either the diazoimidazole or the analogous diazo-1,2,3-triazole, the yield of the azidoheterocycle was low, and the yield of biurea, and presumably the aminoheterocycle, was high. 3-Azidopyrazole-4-carboxamide was obtained from a reaction of hydrazine with the diazopyrazole. Both azido and amino derivatives were formed from reactions of diazo-imidazole esters with hydrazine or thiosemicarbazide. 相似文献
10.
We show that the dipole-dipole interatomic forces induced by an off-resonant running laser beam can lead to a self-bound pencil-shaped Bose condensate, even if the laser beam is a plane wave. For an appropriate laser intensity the ground state has a quasi-one-dimensional density modulation-a Bose-Einstein "supersolid." 相似文献