In social insects, cuticular hydrocarbons are involved in species, kin, caste and nestmate recognition. Gas chromatography and mass spectrometry were used to compare the cuticular hydrocarbon composition of workers, males and queens of Melipona bicolor. The cuticular hydrocarbon composition of this species was found to consist mainly of C23, C25:1, C25, C27:1, C27, C29:1 and C29, which are alre...

INTRODUCTION Many cases of hydrocarbon toxicity occur annually due to oral or inhalational exposure. Rarely are hydrocarbons injected subcutaneously or intravenously. These parenteral routes of exposure, however, can have a wide range of consequences ranging from mild skin irritation to tissue necrosis, pulmonary injury, neurologic consequences, cardiovascular collapse, and death. WD-40TM is a ...

Rat liver microsomes metabolize 3-methylcholanthrene (3MC) to oxygenated forms which alkylate DNA. Analysis of the DNA-bound products by high-pressure liquid chromatography revealed at least 13 deoxyribonucleoside adducts. The two major adducts contained guanine and had fluorescence spectra consistent with saturation at carbon atoms 7, 8, 9, and 10. Microsome-catalyzed binding of 3MC to double-...

biodegradation of petroleum hydrocarbons (20 g/kg dw soil) was investigated in 3 media, differing in the kind of petroleum fractions. in the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synth...

We have studied the effects of vanadate on the rotational motion of the calcium adenosine-triphosphatase (Ca-ATPase) from sarcoplasmic reticulum (SR), using saturation-transfer electron paramagnetic resonance (ST-EPR). Vanadate has been proposed to act as a phosphate analogue and produce a stable intermediate state similar to the phosphoenzyme. This study provides evidence about the physical st...

Horizontal drilling and hydraulic fracturing have enhanced unconventional hydrocarbon recovery but raised environmental concerns related to water quality. Because most basins targeted for shale-gas development in the USA have histories of both active and legacy petroleum extraction, confusion about the hydrogeological context of naturally occurring methane in shallow aquifers overlying shales r...

We examined physiological adaptations which allow the psychrotroph Rhodococcus sp. strain Q15 to assimilate alkanes at a low temperature (alkanes are contaminants which are generally insoluble and/or solid at low temperatures). During growth at 5 degrees C on hexadecane or diesel fuel, strain Q15 produced a cell surface-associated biosurfactant(s) and, compared to glucose-acetate-grown cells, e...

Abstract—The world crude oil demand is projected to rise to 108.5 million bbl/d by the year 2035. With reserves estimated at 869 billion tonnes worldwide, coal remains an abundant resource. The aim of this work was to produce a high value hydrocarbon liquid product using a Direct Coal Liquefaction (DCL) process at, relatively mild operating conditions. Via hydrogenation, the temperature-staged ...

Original SPE manuscript received for review 24 December 2007. Revised manuscript received for review 15 October 2008. Paper (SPE 114802) peer approved 3 December 2008. Summary In this study, we explore an efficient and accurate method for uncertainty analysis of petroleum reservoir simulations. The essence of the approach is the combination of Karhunen-Loeve (KL) expansion and probabilistic col...

The rotational mobility of spin-labeled bovine heart mitochondrial cytochrome e oxidase in purified form, and incorporated into lipid vesicles was studied. A rigidly attached short chain maleimide spin label permitted the measurement of the protein’s overall rotational mobility by saturation transfer electron paramagnetic resonance. A long chain maleimide spin label was used to detect he fluidi...