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1.
Pál Sohár Gábor Bernáth Géza Stájer Angela E. Szabo 《Magnetic resonance in chemistry : MRC》1989,27(9):872-876
Pentacyclic isoxazolines were obtained by the cycloaddition of benzonitrile oxide to norbornene-azetidinone-fused 3,1-oxazines. The constitutions of two of the isomers obtained, and the configurations and conformations of all products, were determined by means of 1H and 13C NMR spectroscopy and DNOE experiments. 相似文献
2.
H. M. Phillips D. L. Callahan R. Sauerbrey G. Szabo Z. Bor 《Applied Physics A: Materials Science & Processing》1992,54(2):158-165
Periodic line structures with a period of 167 nm and linewidths varying from 30 to 100 nm have been produced in polyimide by direct ablation with a KrF laser using an interferometric technique. The characteristics of this interferometer as it applies to the ablation of these line structures, including linewidth and alignment sensitivity, are analyzed. The ability to control the linewidth by varying the average incident fluence is described theoretically and demonstrated experimentally. This externally generated period of 167 nm also prevents the spontaneous growth of laser induced periodic surface structures (LIPSS). 相似文献
3.
4.
L. Moens F. De Corte A. De Wispelaere J. Hoste A. Simonits A. Elek E. Szabo 《Journal of Radioanalytical and Nuclear Chemistry》1984,82(2):385-452
Recommended k0-factors and related nuclear data for use in (n, γ) activation analysis are given for 72 isotopes. In addition the basic nuclear constants and experimental parameters needed in the k0 standardization method are reviewed. For convenient data reduction, computer programs were developed. 相似文献
5.
-[2-(5-Methoxycarbonyl)furyl]-2,4-dihydroxy- and 2,4,6-trihydroxyacetophenones were obtained by the condensation of polyphenols with (2-methoxycarbonyl-5-furyl)acetonitrile. 7-Acetoxy- and 5,7-diacetoxy-2-methyl-3-[2-(5-methoxycarbonyl)furyl]chromones were obtained from them by reaction with acetic anhydride in the presence of triethylamine and were subsequently deacylated to 7-hydroxy and 5,7-dihydroxy compounds. 7-Hydroxy- and 5,7-dihydroxy-2-ethoxycarbonyl-3-[2-(5-methoxycarbonyl)furyl]chromones were obtained from the indicated acetophenones by reaction with ethoxalyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1317–1320, October, 1972. 相似文献
6.
The use of stable isotope-labeled tracer compounds is the safest and most effective method to perform many steady state pharmacokinetic and drug interaction studies. We describe a method by which the heavily deuterated 2H10 analogues of carbamazepine (2H10 CBZ) and phenytoin (2H10 PHT) can be chromatographically separated by high-performance liquid chromatography from unlabeled CBZ and PHT. All compounds are quantitated against an internal standard (IS) (10,11-dihydrocarbamazepine) and measured using conventional UV detection rather than mass spectrometry. Baseline resolution of extracted serum containing 2H10 CBZ, CBZ, 2H10 PHT, PHT and IS is achieved on a heated (55 degrees C) 25 cm x 4.6 mm BioAnalytical Systems Phase II 5 microns ODS column with an isocratic mobile phase consisting of water-acetonitrile-tetrahydrofuran (80:16:4, v/v/v) at 1.2 ml/min. Eluting compounds were monitored at a UV wavelength of 214 nm. Calculated resolution of 2H10 CBZ from CBZ and of 2H10 PHT from PHT were 1.3. Serum standard curves were linear (R greater than or equal to 0.999) over a range of 0.5-14 micrograms/ml for 2H10 CBZ, 0.5-20 micrograms/ml for CBZ, 0.5-20 micrograms/ml for 2H10 PHT, and 0.5-30 micrograms/ml for PHT. Within-day percent relative standard deviations (precision) were less than 6% in all cases. 相似文献
7.
Accurate urinary measurements of the two major metabolites of phenytoin, 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) and 5-(3,4-dihydroxy-cyclohexa-1,5-dienyl)-5-phenylhydantoin (dihydrodiol, DHD), are necessary for pharmacokinetic and drug-interaction studies of this commonly used antiepileptic drug. We describe a simple, rapid, acid hydrolysis, with liquid-liquid extraction and simultaneous isocratic reversed-phase high-performance liquid chromatography of p-HPPH and 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) (hydrolytic end product of DHD). p-HPPH and m-HPPH were quantitated against their separate respective internal standards of alphenal and tolylbarb. The mobile phase consisted of water-dioxane-tetrahydrofuran (80:15:5, v/v/v) at 2 ml/min and at 50 degrees C, with detection at 225 nm. Baseline separation was achieved by use of a 16 cm x 3.9 mm Nova-Pak C18 column and total analysis time of 12 min. p-HPPH and m-HPPH concentrations ranged from 10 to 200 and from 2 to 30 micrograms/ml, respectively, with between-day coefficients of variations of 3.3-4.5% and 2.2-5.1% for controls. All standard curves were linear with r values greater than 0.993. The DHD concentration was determined by multiplying m-HPPH concentrations by 2.3. 相似文献
8.
Salo Gronowitz Kalman J. Szabo James O. Oluwadiya 《Journal of heterocyclic chemistry》1991,28(2):351-352
The nitration of dithieno[3,4-b:3′,2′-d]pyridine ( 2 ) and dithieno[2,3-b:3′,2′-d]pyridine ( 3 ) has been studied. Nitration of 2 occurred in both positions of the c-fused thiophene ring, while 3 was predominantly substituted in the 2-position. The structures of the nitro derivatives were proven by extensive use of 1H and 13C nmr spectroscopy. 相似文献
9.
Reactive constituents have been investigated in a molecular beam generated in the cathode surface glow area and surface boundary layer. Mixtures of nitrogen and hydrogen form NHx(x=0–4) compounds, which are of relevance in heterogeneous, plasma vs. metal nitriding reactions. Ammonia decomposition leads to NHx(x=2–4). Strong cataphoretic enrichment of hydrogen has been observed in the cathode glow area. Heterogeneous reactions of NHx with iron lead to the formation of iron nitrides via intermediates such as FeNH2–3. In a pulsed d.c. glow discharge, increased sputtering and decreased hydrogen enrichment have been observed. 相似文献
10.
G. Čík J. Lesný F. Šeršeň L. Szabo 《Journal of Radioanalytical and Nuclear Chemistry》1994,186(2):175-182
The influence of -radiation on the electric properties of Langmuir-Blodgett (LB) films of partially iodine-doped poly-(3-hexadecylthiophene) and stearic acid in interaction with selected environment-polluting gases has been studied. CO2, CO and NO2 increase the LB films conductivity and NO has a tendency to decrease the electric conductivity. The influence of -radiation was expressive onyl in the case of CO2, whereas NO2 brought about degradation of the conductive polymer. 相似文献