نتایج جستجو برای: hydrocarbons
تعداد نتایج: 26785 فیلتر نتایج به سال:
Objective(s):Various species of genus Trigonella are important from medical and culinary points of view. The essential oil of Trigonella torbatejamensis Ranjbar as an endemic plant in Iran has not been studied previously. The essential oil of this plant was analyzed by different methods for identification of its components. Materials and Methods: The essential oil composition of aerial parts o...
altan derivatives of polycyclic conjugated hydrocarbons were recently introduced and studied in theoretical organic chemistry. we now provide a generalization of the altan concept, applicable to any graph. several earlier noticed topological properties of altan derivatives of polycyclic conjugated hydrocarbons are shown to be the properties of all altan derivatives of all graphs. among these ar...
The copper-catalyzed tandem oxidative cyclization of cinnamamides with benzyl hydrocarbons through the direct cross-dehydrogenative coupling of sp(3) and sp(2) C-H bonds has been developed. Satisfactorily, ethers, alcohols and alkanes could also be used instead of benzyl hydrocarbons in this transformation, which allows rapid access to diverse dihydroquinolinones in one step.
Two-dimensional arrays consisting of strongly subspectral molecular graphs and formula periodic tables for polycyclic aromatic hydrocarbons are briefly reviewed. New two-dimensional arrays for free-radical benzenoid hydrocarbons are presented with general analytical expressions for counting their number of resonance structures (SC). The structural origin of the coefficients to these analytical ...
Co-oxidation is a little understood means of microbial degradation of petroleum hydrocarbons. In co-oxidation, microbes growing on one compound, the growth substrate, are able to oxidize a second · compound, the cosubstrate. This project examines the role of co-oxidation in the degradation of polycyclic aromatic hydrocarbons (PAR's), one of the most recalcitrant petroleum compounds now found in...
Magnetically induced current densities have been calculated for a series of hydrocarbons consisting of hexadehydro[12]annulene rings alternatingly fused with benzenes. The calculations show that all molecular rings of the studied molecules sustain paramagnetic ring currents. The new class of molecules is therefore coined polycyclic antiaromatic hydrocarbons (PAAH).
Attempts to induce liver tumors with the car cinogenic polycyclic aromatic hydrocarbons have generally failed (9). However, certain of these hydrocarbons have a marked effect on hepatic carcinogenesis induced by other agents. Thus, Richardson et al. (32) observed that 3-methylcholanthrene1 (MC), administered at a low level to rats also receiving the strong hepatocarcinogen 3'-methyl-4-dimethyla...
I t has been established that water-insoluble carcinogens and their metabolic products are transported in the blood following their administration to animals (4). Set~l~i and Ermala found that hydrocarbons, when fed, enter the circulation by a route similar to that of dietary fats (9). These investigators observed fluorescence in chylomicrons in lymph and serum obtained from animals after inges...
Biomarker molecules are valuable for the elucidation of ancient microbial ecosystems and the characterization of petroleum source rocks. For such studies, acquisition of reliable hydrocarbon data and proof of their syngeneity are essential. However, contamination of geological samples with anthropogenic petroleum products during drilling, storage and sampling can be particularly problematic bec...
The cuticular hydrocarbons (CHs) and morphology of two Ceratitis rosa Karsch (Diptera: Tephritidae) populations, putatively belonging to two cryptic taxa, were analysed. The chemical profiles were characterised by two-dimensional gas chromatography with mass spectrometric detection. CHs of Ceratitis rosa that originated from the lowlands and highlands of Kenya comprised of n-alkanes, monomethyl...
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