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81.
Dimorphamides A–C ( 1 – 3 , resp.), three new polyphenolic amides, have been isolated from the BuOH‐soluble fraction of the whole plant of Atriplex dimorphostagia, along with two known compounds, thymidine and N‐[(E)‐feruloyl]tyramine. Their structures have been determined on the basis of spectral studies. 相似文献
82.
Shamsher S. Bari Mehmood S. Magtoof Aman Bhalla 《Monatshefte für Chemie / Chemical Monthly》2010,8(6):987-991
Abstract
An operationally simple and efficient approach for the synthesis of azetidin-2,3-diones is described. The starting substrate 2-(2-bromobenzyloxy)ethanoyl chloride was treated with appropriate Schiff’s bases in triethylamine and dichloromethane to afford 3-(2-bromobenzyloxy)azetidin-2-ones. The synthesis of azetidin-2,3-diones was successfully achieved via radical mediated rearrangement of appropriately substituted 3-(2-bromobenzyloxy)azetidin-2-ones using n-tributyltin hydride and AIBN in refluxing dry benzene. 相似文献83.
Auguste Aman 《Journal of Theoretical Probability》2012,25(4):1153-1172
In this paper, we study reflected generalized backward doubly stochastic differential equations driven by Teugels martingales associated with Lévy process (RGBDSDELs in short) with one continuous barrier. Under uniformly Lipschitz coefficients, we prove an existence and uniqueness result by means of the penalization method and the fixed-point theorem. As an application, this study allows us to give a probabilistic representation for the solutions to a class of reflected stochastic partial differential integral equations (SPDIEs in short) with a nonlinear Neumann boundary condition. 相似文献
84.
Aman CS Pastor A Cighetti G de la Guardia M 《Analytical and bioanalytical chemistry》2006,386(6):1869-1879
A sensitive, specific and selective multianalyte GC–MS/MS method has been developed for the determination of 11 anabolic hormones
in bovine urine. After adjusting the urine pH to 4.8, the samples were spiked with deuterated internal standards and submitted
to enzymatic hydrolysis with β-glucuronidase/arylsulfatase. Hormones were eluted with methanol through a C18 solid phase cartridge
and submitted to a liquid–liquid extraction. Analytes were derivatized by adding N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane and GC–MS data were obtained in the positive
electron impact tandem mass mode. Under these conditions, no matrix effects were observed and limit of detection values were
in the range of 0.005 ng/mL (diethylstilbestrol) to 0.38 ng/mL (17α-methyltestosterone and 17α-ethynylestradiol). Recoveries
from 81% (α-zeranol) to 149% (17α-methyltestosterone) were found under the selected conditions. These results were better
than those found using heptafluorobutyric anhydride (HFBA) as derivative reagent and those measured in full scan and selective
ion monitoring modes. 相似文献
85.
86.
87.
Iqbal A Clifton IJ Chowdhury R Ivison D Domene C Schofield CJ 《Organic & biomolecular chemistry》2011,9(18):6219-6225
Structural and biochemical analyses reveal how ornithine acetyl-transferases catalyse the reversible transfer of an acetyl-group from a basic (ornithine) to an acidic (glutamate) amino acid by employing a common mechanism involving an acetyl-enzyme intermediate but using different side chain binding modes. 相似文献
88.
Ioan Pop Anuar Ishak Fazlina Aman 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2011,62(5):953-956
This paper considers the effects of radiation on the flow near the two-dimensional stagnation point of a stretching sheet immersed in a viscous and incompressible electrically conducting fluid in the presence of an applied constant magnetic field. The external velocity and the stretching velocity of the sheet are assumed to vary linearly with the distance from the stagnation point. The governing partial differential equations are transformed into a system of ordinary differential equations using a similarity transformation, before being solved numerically by the Keller-box method. The features of the heat transfer characteristics for different values of the governing parameters are analyzed and discussed. The results indicate that the heat transfer rate at the surface decreases in the presence of radiation. 相似文献
89.
Ioan Pop Anuar Ishak Fazlina Aman 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2011,43(4):953-956
This paper considers the effects of radiation on the flow near the two-dimensional stagnation point of a stretching sheet
immersed in a viscous and incompressible electrically conducting fluid in the presence of an applied constant magnetic field.
The external velocity and the stretching velocity of the sheet are assumed to vary linearly with the distance from the stagnation
point. The governing partial differential equations are transformed into a system of ordinary differential equations using
a similarity transformation, before being solved numerically by the Keller-box method. The features of the heat transfer characteristics
for different values of the governing parameters are analyzed and discussed. The results indicate that the heat transfer rate
at the surface decreases in the presence of radiation. 相似文献
90.