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Male choosiness of prospective female mating partners provides an increasingly recognized pathway through which males can increase their fitness. For example, males may increase their number of offspring by targeting more fecund females as mating partners. If fecundity is heritable, males that mate with more fecund females can also receive the indirect benefit of more fecund daughters. In species where female fecundity is not directly assessable, female ornaments may act as signals of fecundity. However, whether female ornaments reliably signal the indirect benefit of more fecund daughters is not well understood. We investigated this question using the field cricket, Teleogryllus oceanicus. Previous work had identified the cuticular hydrocarbon (CHC) profile as a female sexual display trait in T. oceanicus. To examine whether CHCs can provide a reliable signal of fecundity, we tested whether individual CHC compounds and the first principal axis of CHC variation (PC1) are genetically correlated with ovary mass, a reliable proxy for fecundity in this species. We found significant genetic correlations between ovary mass and three individual CHC compounds, as well as PC1. This result indicates that by targeting females as mating partners based on their CHC profile, males can sire more fecund daughters. [ABSTRACT FROM AUTHOR]

Abstract The mediator of dioxin toxicity, aryl hydrocarbon receptor (AHR), has also important physiological functions. Selective AHR modulators (SAHRMs) share some effects of dioxins, except for their marked toxicity. We recently characterised toxicologically two novel SAHRMs, prodrugs IMA-08401 and IMA-07101 in rats, demonstrating that they are far less deleterious than the most toxic AHR-agonist, TCDD. Here, we analysed the in vitro toxicity and in silico AHR binding of the respective active, deacetylated metabolites, IMA-06201 (N-ethyl- N -phenyl-5-chloro-1,2-dihydro-4-hydroxy-1-methyl-2-oxo-quinoline-3-carboxamide) and IMA-06504 (N-(4-trifluoromethylphenyl)-1,2-dihydro-4-hydroxy-5-methoxy-1-methyl-2-oxo-quinoline-3-carboxamide). In H4IIE rat hepatoma cells, IMA-06201 and IMA-06504 induced CYP1A1 with comparable potencies and efficacies to those of TCDD. They had little effect on cell viability as assessed by LDH leakage and MTT reduction assays, and were not mutagenic in the Ames test, but IMA-06504 elicited a maximally 2.7-fold increase in micronuclei. Molecular docking simulations showed that similar to TCDD, they occupy the central region of AHR ligand binding cavity. Hence, while showing low to negligible in vitro toxicity, these novel SAHRMs bind to the AHR qualitatively in a similar fashion to TCDD, and appear comparably powerful AHR agonists. Combined with our earlier results demonstrating that they seem considerably less toxic in vivo than TCDD, these compounds are thus highly interesting new SAHRMs. Highlights • IMA-06201 and IMA-06504 are selective AHR modulators. • As CYP1A1 inducers, they appear comparable to TCDD in potency and efficacy. • They also show low to negligible cytotoxicity and mutagenicity in vitro. • Based on in silico modelling, their binding to the AHR resembles that of TCDD. • Therefore, they have potential as drug compound candidates and research tools. [ABSTRACT FROM AUTHOR]

The compositions of polycyclic aromatic hydrocarbons used as chemical markers for the identifying of different sources in the surface seawater of Alexandria coastal area. The quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) showed a concentration ranged from 8970.939-1254756.00 ng/L, which exceed the maximum admissible concentrations of PAHs (200 ng/L) for the water standard of European Union. The calculated diagnostic ratios suggested that the sources of PAHs at the majority of the studied area are derived primarily from pyrogenic sources from incomplete fuel combustion of the boats and vehicle engines with lesser amounts of PAHs contributed from petrogenic sources. Some stations displayed mixed sources in comparison to many other studied marine systems, the PAHs concentrations detected at Alexandria area were considered be higher to pose health risks to aquatic bodies. [ABSTRACT FROM AUTHOR]

The paper is concerned with the study of triboluminescence of lanthanide salts in an atmosphere of hydrocarbon gases (methane, its homologues, ethylene, and acetylene). The luminescence of *CH and/or *C 2 appeared after mechanochemical decomposition of these gases during tribodestruction of crystals was observed in all the gases. Injection of hydrocarbon gases suppressed the glow of *N 2 (a gas component in a triboluminescence spectrum of air). When heavier hydrocarbon gases were used, the triboluminescence spectra indicated that *C 2 emission predominated over the luminescence of a *CH radical. The intensity of *C 2 emission decreased with an increase in a hydrocarbon chain. The decomposition mechanism of hydrocarbon gases to form *CH and *C 2 during triboluminescence of lanthanide salts in the atmosphere of these gases is discussed. A similar decomposition mechanism of these gases in electric discharges is also discussed. The experimental spectra of the *C 2 (Swan bands) were used to calculate and to estimate some characteristics of the radiating medium. The vibrational temperatures T vib ~ 4000–5000 K calculated for different hydrocarbon gases exceeded the rotational one T rot ˂ 3000 K. This indicates that the working medium is a nonequilibrium plasma, in which the C 2 excitation occurs due to electron impact. In addition, it was assumed that the excitation could also be caused by collision with heavy particles, for example, hot gas molecules as a result of gas heating during a series of consecutive experiments. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants that occur in complex mixtures. Several PAHs are known or suspected mutagens and/or carcinogens, but developmental toxicity data is lacking for PAHs, particularly their oxygenated and nitrated derivatives. Such data are necessary to understand and predict the toxicity of environmental mixtures. 123 PAHs were assessed for morphological and neurobehavioral effects for a range of concentrations between 0.1 and 50 µM, using a high throughput early-life stage zebrafish assay, including 33 parent, 22 nitrated, 17 oxygenated, 19 hydroxylated, 14 methylated, 16 heterocyclic, and 2 aminated PAHs. Additionally, each PAH was evaluated for AHR activation, by assessing CYP1A protein expression using whole animal immunohistochemistry (IHC). Responses to PAHs varied in a structurally dependent manner. High-molecular weight PAHs were significantly more developmentally toxic than the low-molecular weight PAHs, and CYP1A expression was detected in five distinct tissues, including vasculature, liver, skin, neuromasts and yolk. [ABSTRACT FROM AUTHOR]

Some efforts made to date in curbing greenhouse gases from the transportation sector have focused on the production of biofuels. Biomass derived oils have advantages that outweigh their flaws as fuels. Petroleum range hydrocarbons can be produced via secondary processing of bio-oils. Feedstock type and availability, catalyst choice and operating conditions have a significant influence on the potentials of biomass as a feedstock for petroleum Range hydrocarbons. Despite numerous works done, it is noted that more research is needed towards commercialising biomass conversion techniques with the view to producing petroleum range hydrocarbon and biomass like algae and palm oil have been seen to be very promising sources of biofuels. [ABSTRACT FROM AUTHOR]

Biogenic emissions affect the urban air quality as they are ozone and secondary organic aerosol (SOA) precursors and should be taken into account when applying photochemical pollution models. The present study presents an estimation of the magnitude of non-methane volatile organic compounds (BNMVOCs) emitted by vegetation over Greece. The methodology is based on computation developed with the aid of a Geographic Information System (GIS) and theoretical equations in order to produce an emission inventory on a 6 × 6 km2 spatial resolution, in a temporal resolution of 1 h covering one year (2016). For this purpose, a variety of input data was used: updated satellite land-use data, land-use specific emission potentials, foliar biomass densities, temperature, and solar radiation data. Hourly, daily, and annual isoprene, monoterpenes, and other volatile organic compounds (OVOCs) were estimated. In the area under study, the annual biogenic emissions were estimated up to 472 kt, consisting of 46.6% isoprene, 28% monoterpenes, and 25.4% OVOCs. Results delineate an annual cycle with increasing values from March to April, while maximum emissions were observed from May to September, followed by a decrease from October to January. [ABSTRACT FROM AUTHOR]

The influence of thermal conditions on the anodic behavior of aluminum in sodium hydrocarbonate solutions of various concentrations was studied. The concentration and temperature limits of local activation in the studied systems are established. The effect of the thermal activation of self-dissolving metal is found. [ABSTRACT FROM AUTHOR]

Pyrene, a member of the polycyclic aromatic hydrocarbons (PAHs), contributes to abnormality in the size of the brain and the swimming behavior of pufferfish ( Takifugu niphobles ) larvae. We hypothesized that the aryl hydrocarbon receptor (AHR) may mediate pyrene-induced toxic effects because AHR is assumed to be a candidate for the downstream target of PAHs in many cases. To identify the contribution of AHR on developing pufferfish, we performed exposure experiments using β-naphthoflavone, an agonist of AHR. We found that the toxic effects of pyrene and β-naphthoflavone in pufferfish larvae are fundamentally different. Pyrene specifically induced problems in the developing midbrain and in swimming behavior, while β-naphthoflavone affected the heartbeat rate and the size of the yolk. These results suggest that the behavioral and morphological abnormality caused by pyrene exposure is mediated by an AHR-independent pathway. Alternatively, defects caused by pyrene may be attributed to the inhibition of the FGF signal. [ABSTRACT FROM AUTHOR]

Aims Study the response of microbial communities and selected petroleum hydrocarbon ( PH)-degrading genes on simulated PH spills in soils/sediments from different geographic locations. Methods and Results A microcosm experiment was conducted by spiking mixtures of petroleum hydrocarbons (PHs) to soils/sediments collected from four different regions of China, including the Dagang Oilfield ( DG), Sand of Bohai Sea ( SS), Northeast China ( NE) and Xiamen ( XM). Changes in bacterial community and the abundance of PH-degrading genes ( alkB, nah and phe) were analysed by denaturing gradient electrophoresis ( DGGE) and qPCR, respectively. Degradation of alkanes and PAHs in SS and NE materials were greater ( P < 0·05) than those in DG and XM. Clay content was negatively correlated with the degradation of total alkanes by 112 days and PAHs by 56 days, while total organic carbon content was negatively correlated with initial degradation of total alkanes as well as PAHs. Abundances of alkB, nah and phe genes increased 10- to 100-fold and varied by soil type over the incubation period. DGGE fingerprints identified the dominance of α-, β- and γ- Proteobacteria (Gram −ve) and Actinobacteria (Gram +ve) bacteria associated with degradation of PHs in the materials studied. Conclusion The geographic divergence resulting from the heterogeneity of physicochemical properties of soils/sediments appeared to influence the abundance of metabolic genes and community structure of microbes capable of degrading PHs. Significance and Impact of the Study When developing practical in-situ bioremediation approaches for PHs contamination of soils/sediment, appropriate microbial community structures and the abundance of PH-degrading genes appear to be influenced by geographic location. [ABSTRACT FROM AUTHOR]

Optimum production from a hydrocarbon field takes place when technical parameters are optimized with respect to the operational and economic constraints. Well control parameters have an important role in making decisions for choosing efficient production scenario in a reservoir. Among the economical constraints cost of drilling and completion of wells, transportation and refinery costs and price of oil and gas can be named. In this paper, using single well model, the design of experiments and multi criteria decision making, determination of optimum production scenario based on a sector of South Pars gas field is addressed. Flow rate, well spacing, minimum wellhead pressure, production string size, deviation of wells and type of stimulation are decision parameters that are considered in this study. Economic indices chosen for economic analysis are net present value, internal rate of return and plateau time. First using the design of experiments and response surface methodology, proxy models are generated to predict economic indices for production scenarios and after validation of them, they are used for economic analysis and choosing the best scenario based on multi-criteria decision making. [ABSTRACT FROM AUTHOR]

After analyzing the molecular and isotopic compositions of 11 gas samples from Baka Gas Field, as well as the low molecular weight hydrocarbons (LMWHs) associated with them, the two types of natural gases are identified: biodegraded and non-biodegraded gases. No distinctions in molecular and isotopic compositions are observed between biodegraded and non-biodegraded methane, which may be partially due to the great solubility of methane in water. Anomalous molecular compositions and carbon and hydrogen isotopic ratios are observed among the biodegraded C 2+ gas components, which become more significantly fractionated in propane than in ethane, most probably due to their selective depletion by different strains of bacteria. The biodegradation resistance for C 6 –C 7 LMWHs associated with gases from Baka Gas Field follow the series Dimethylbutanes > Cyclohexane > Methylcyclopentane > 2-Methylpentane > 3-Methylpentane; Dimethylpentanes, 1,1-Dimethylcyclopentane and 1,2-Dimethylcyclopentanes > Methylcyclohexane >1,3-Dimethylcyclopentanes > 2-Methylhexane > 3-Methylhexane, respectively. Within the identical carbon numbers, two characteristics of biodegradation susceptibility for C 6 –C 7 LMWHs are observed: total poly-branched alkanes are more resistant to biodegradation than cycloalkanes, and mono-branched ones tend to be depleted by bacteria more easily than cycloalkanes; and isomers with adjacent methyl groups tend to be more resistant to biodegradation. These two characteristics could be effective tools for the identification of biodegraded hydrocarbons and for the determination of the degree of bacterial decomposition. After comparison with previous studies, it is evident that the varieties in bacteria strains result in the discrepancy of biodegradation efficiency for certain light hydrocarbon isomers. This research improves the understanding of the geochemical characteristics of biodegraded gases and provides additional tools for the identification of biodegraded gases and their degree of biodegradation. [ABSTRACT FROM AUTHOR]

The comprehensive performance of mechanical screens is extremely important for sand control and well completion and to the screen's service life. Screen sand retaining media are analyzed and divided into several classifications. The concepts of sand retaining ability, anti-plugging ability, and flow capacity are put forward to describe screen comprehensive performance. A new experimental method is set up to test the comprehensive performance of mechanical screens. During the test, formation sand is carried by fluid that flows radially against the screen to simulate the real process of sand retaining. The variation of flow rate, pressure difference through screen media, and permeability with time reflect the screen's dynamic characteristics. Based on test data, a set of evaluation indexes is proposed to describe the conductivity, sand retaining, anti-plugging ability, and relevant comprehensive performance of screens. The calculation method is also developed. This new integrated methodology for comprehensive performance evaluation was successfully applied in the selection of optimum screen type for a given reservoir. This method needs only a small number of tests and provides an effective means for evaluating and selecting an optimum screen type for reservoirs. [ABSTRACT FROM AUTHOR]

The analysis of multiple cracks in a heat exchanger tubeplate at a petrochemical plant led to experimental replication of in-service damage. High lifting stresses created a first leak that was repaired. Extended branched intergranular cracking developed from the tubeplate surface around the repair weld after few weeks of renewed operation. Chemical analyses failed to detect Na on crack surfaces, while operative conditions also allowed discarding a typical SCC cracking mechanism. Lack of radial interference between tubes and plate, lack of penetration and lack of fusion at tube to tubeplate weld roots were also thought as contributors to cracking. Microstructural analyses revealed martensite clusters in welds and HAZ, and austenite grain boundary precipitates in the tubeplate base material. Thermal cycles were applied to ex-service samples to replicate the conditions for these brittle micro constituents, which were found to be unstable at operating temperatures. Mechanical testing also replicated grain boundary weakness. This inadequate structure was related to welding without proper thermal cycles and heat treatments. [ABSTRACT FROM AUTHOR]

The present study reports the genetic damage and the concentrations of trace metals and total petroleum hydrocarbons prevailing in natural populations of an edible fish, Arius arius in different seasons along the coast of Goa, India as an indicator of the pollution status of coastal water. Fish were collected from a suspected polluted site and a reference site in the pre-monsoon, monsoon and post-monsoon seasons. Physico-chemical parameters as well as the concentrations of total petroleum hydrocarbons (TPH) and trace metals in the water and sediment as well as the tissues of fish collected from these sites were recorded. The genotoxicity status of the fish was assessed employing the micronucleus test and comet assay. A positive correlation (p<0.001) was observed between the tail DNA and micronuclei in all the fish collected. Multiple regression analysis revealed that tissue and environmental pollutant concentrations and genotoxicity were positively associated and higher in the tissues of the fish collected from the polluted site. Pollution indicators and genotoxicity tests, combined with other physiological or biochemical parameters represent an essential integrated approach for efficient monitoring of aquatic ecosystems in Goa. [ABSTRACT FROM AUTHOR]

The reforming of diesel and diesel-like fuels plays a central role in the development of fuel cell systems for on-board power supplies. The vaporization of the fuel via a spray formation and the subsequent mixture with water vapor and air determine the quality of the reforming process, as is shown in this paper. By using a high quality nozzle residual hydrocarbons were below 25 ppmV during the reforming of standard diesel. Through the use of a fuel injector in pulsed operation, the load range was able to be increased from 1:1.67 to 1:6. Spray pattern analyses were conducted using a high-speed camera. The formation of the spray pattern lasted 1.5–2 ms. The testing of a fast-closing magnetic valve manufactured by GSR Ventiltechnik was carried out on the autothermal reformer (ATR) type AH2. It exist not any direct influence of the pulsed operation on hydrogen production. [ABSTRACT FROM AUTHOR]

In order to obtain the precise predicted values of methane/hydrogen/air burning velocities from simulations, the performances of GRI mech 3.0, Aramco mech 1.3, USC mech 2.0 and San diego mech mechanisms were systematically studied under various conditions by PREMIX code and compared with experimental data from literature. The conditions where each mechanism gave their good performance are obtained and concluded. The flowrate sensitivity and rate constants of key elementary reactions were analyzed to insight the different behavior of each mechanism. The results showed that all these widely used small hydrocarbon mechanisms could gave reasonable predictions for pure methane and methane hydrogen blends. Nevertheless, they lack sensitivity for rich hydrogen at elevated pressures due to their complex reactions competitions controlled by hydrogen sub model. USC mech 2.0 was found more suitable for being used at low hydrogen contents while San diego mech gained better results at high hydrogen contents. GRI 3.0 gave good predictions for methane hydrogen blends except for high initial pressures. Generally, Aramco mech 1.3 showed the best performance for all testing conditions. Moreover, there was relatively large deviation from the predicted results and experimental data in the transition regime where the hydrogen fractions were between 60% and 80%, it may could be optimized by tuning the rate constants of reactions. [ABSTRACT FROM AUTHOR]

Hydrocarbon contamination accumulated on titanium (Ti) implant surfaces during storage and sterilization is unavoidable and difficult to remove. It impairs the bioactivity of implants, restricts initial interactions between implants and the surrounding biological environment, and has become a common challenge for Ti implants. To overcome this problem, sterilization was considered as the final surface modification and a novel method, hydrothermal sterilization (HS), was proposed. Briefly, stored sandpaper-polished Ti specimens were sterilized in a glass container with pure water at 121 °C for 20 min and kept in the same water until utilization. As a control, another group of specimens was sterilized with conventional autoclaving (AC) at 121 °C for 20 min and stored in sterilization pouches after being dried at 60 °C. Compared with AC, HS deposited numerous nano-sized particles on the substrates, reduced the atomic percentage of the surface carbon, and transformed the Ti surface to a super hydrophilic status. HS also increased the attachment rate, spread, proliferation, and the mineralized nodule areas of rat bone marrow-derived osteoblasts. These results suggest that HS enhances the bioactivity of Ti implants for osteoblasts, and that this biofunctionalization was attributed to nanostructure construction, hydrophilic conversion, and the effective removal of hydrocarbons. Hydrothermal sterilization is proposed to be used as a universal sterilization method for all kinds of titanium implants without apatite coating. [ABSTRACT FROM AUTHOR]

Background Mycosis fungoides ( MF) is the most frequent type of cutaneous T-cell lymphoma. MF has long been considered to develop as the result of a combination of genetic defects and exogenous triggers. Although no specific MF-associated environmental trigger has been established to date, some studies have suggested that occupational exposures may occasionally trigger the onset of MF. Objective In this observational study, we aimed at underscoring the potential association between occupational exposure and MF. Methods We ascertained a cohort of 150 MF patients for possible occupational exposure. Results Five MF patients with occupational exposure were identified in our cohort. Three patients had intensive contact with aromatic hydrocarbons; two of them were working in the same plant and in the same unit for more than 30 years. The third patient had been in contact with aromatic hydrocarbons for a total of 8 years. Patient 4 had additional contact for 12 years with hydrazine, and patient 5 had been exposed for 3 years to formaldehyde. Conclusion The clustering of two cases of MF, an exceptionally rare disease, in the same plant unit, as well as the long-term, intense occupational exposure in other cases, substantiates the notion that occupational exposures may contribute to the pathogenesis of MF. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Self-reported smoking underestimates disease risk. Smoking affects DNA methylation, in particular the cg05575921 site in the aryl hydrocarbon receptor repressor (AHRR) gene. We tested the hypothesis that AHRR cg05575921 hypomethylation is associated with risk of smoking-related morbidity and mortality.Methods: From the Copenhagen City Heart Study representing the Danish general population, we studied 9234 individuals. Using bisulphite treated leucocyte DNA, AHRR (cg05575921) methylation was measured. Rs1051730 (CHRN3A) genotype was used to evaluate smoking heaviness. Participants were followed for up to 22 years for exacerbations of COPD, event of lung cancer and all-cause mortality. Six-year lung cancer risk was calculated according to the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCOM2012).Measurements and Main Results: AHRR (cg05575921) hypomethylation was associated with former and current smoking status, high daily and cumulative smoking, short time since smoking cessation (all p values <7×10-31), and the smoking-related CHRN3A genotype (-0.48% per T-allele, p=0.002). The multifactorially adjusted HRs for the lowest versus highest methylation quintiles were 4.58 (95% CI 2.83 to 7.42) for COPD exacerbations, 4.87 (2.31 to 10.3) for lung cancer and 1.67 (1.48 to 1.88) for all-cause mortality. Finally, among 2576 high-risk smokers eligible for lung cancer screening by CT, observed cumulative incidences of lung cancer after 6 years for individuals in the lowest and highest methylation quintiles were 3.7% and 0.0% (p=2×10-7), whereas predicted PLCOM2012 6-year risks were similar (4.3% and 4.4%, p=0.77).Conclusion: AHRR (cg05575921) hypomethylation, a marker of smoking behaviour, provides potentially clinical relevant predictions of future smoking-related morbidity and mortality. [ABSTRACT FROM AUTHOR]

The present paper investigated on the presence of some hydrocarbon contaminants, namely polycyclic aromatic hydrocarbons (PAHs), mineral oil hydrocarbons (MOH) comprising saturated (MOSH) and aromatic (MOAH) compounds, and polyolefin oligomeric saturated hydrocarbons (POSH) in olives and extra virgin olive oils from Tunisia. Olive fruits were collected in sites exposed to different environmental contamination, and the oil extracted both by physical mean (using an Abencor extractor) and with solvent (using microwave assisted extraction, MAE). Analytical determination was performed by SPE cleanup on silica cartridge followed by spectrofluorometric detection, for PAH, and on-line HPLC-GC-FID for MOH and POSH. Oils extracted from olives by physical mean, as well as extra virgin olive oils from the market, had PAH levels never exceeding the EU legal limits. All olive samples showed similar MOSH profiles, but not clear correlation between the variable contamination levels and considered sources of contamination, was evidenced. The average MOSH content in oil extracted from olives by solvent (11.1 mg/kg) was about four time higher than in oil extracted by physical mean (2.6 mg/kg). MOSH in extra virgin oil from the market ranged from 10.3 to 38.0 mg/kg, while MOAH were not detected. The higher MOSH levels found in oils from the market evidenced an important contribution due to oil processing and/or packaging. Two of the samples were clearly contaminated with polyolefin oligomeric hydrocarbons (POSH) migrated from the plastic cap. [ABSTRACT FROM AUTHOR]

The Liaodong Bay sub-basin is one of the most petroliferous sub-basins in the Bohai Bay basin. The fourth member of the Eocene Shahejie Formation (E 2 s 4 , 50.5–42 Ma) which is an important source rock interval in other sub-basins was rarely studied in the Liaodong Bay sub-basin. The hydrocarbon generating potential, biomarker assemblage and accumulation contribution for discovered oil fields of the E 2 s 4 source rock interval in the Liaodong Bay sub-basin were studied using geological and geochemical data. The E 2 s 4 source rocks in the Liaodong Bay sub-basin display relatively high total organic carbon contents (TOC) and Rock-Eval hydrogen indices (HI) and can be considered as a set of excellent oil-prone tendency source rocks. The source rocks interval is characterized mainly by relatively low Pristane/Phytane (Pr/Ph), C 19 /C 23 tricyclic terpane (C 19 /C 23 TT), C 24 tetracyclic terpane/C 26 tricyclic terpane (C 24 Tet/C 26 TT), low to medium hopane/sterane (H/S), medium 4-methyl steranes/ΣC 29 steranes ratio (4-MS/ΣC 29 ST), C 35 22S/C 34 22S hopane (C 35 /C 34 SH) and high gammacerane/αβC 30 hopane (G/H), extended tricyclic terpane ratio [ETR=(C 28 TT + C 29 TT)/(C 28 TT + C 29 TT + Ts)] and were deposited in anoxic to sub-oxic saline-water environment with no or minor terrigenous organic matter and medium dinoflagellate input. The maturity of E 2 s 4 source rocks in the Liaozhong and north Liaoxi sags is too high to provide oils for fields. The E 2 s 4 source rocks in the south and middle Liaoxi sag displayed opportune maturity within the oil window and were proved by oil-source correlation having important accumulation contribution for discovered oil fields in this area. The E 2 s 4 -derived oils should be taken seriously in the future exploration in the south and middle Liaoxi sag and on adjacent uplifts. [ABSTRACT FROM AUTHOR]

Crude oil contamination widely impacts soil as a result of release during oil and gas exploration and production activities. The success of bioremediation methods to meet remediation goals often depends on the composition of the crude oil, the soil, and microbial community. Earthworms may enhance bioremediation by mixing and aerating the soil, and exposing soil microorganisms to conditions in the earthworm gut that lead to increased activity. In this study, the common composting earthworm Eisenia fetida was tested for utility to improve remediation of oil-impacted soil. E . fetida survival in soil contaminated with two distinct crude oils was tested in an artificial (lab-mixed) sandy loam soil, and survival compared to that in the clean soil. Crude oil with a high fraction of light-weight hydrocarbons was more toxic to earthworms than the crude oil with a high proportion of heavy polyaromatic and aliphatic hydrocarbons. The heavier crude oil was added to soil to create a 30,000 mg/kg crude oil impacted soil, and degradation in the presence of added earthworms and feed, feed alone, or no additions was monitored over time and compared. Earthworm feed was spread on top to test effectiveness of no mixing. TPH degradation rate for the earthworm treatments was ~ 90 mg/day slowing by 200 days to ~ 20 mg/day, producing two phases of degradation. With feed alone, the rate was ~ 40 mg/day, with signs of slowing after 500 days. Both treatments reached the same end point concentrations, and exhibited faster degradation of aliphatic hydrocarbons < C21, but all fractions, including aromatics > C21, decreased. During these experiments, soils were moderately toxic during the first three months, then earthworms survived well, were active and reproduced with petroleum hydrocarbons present. This study demonstrated that earthworms accelerate bioremediation of crude oil in soils, including the degradation of the heaviest polyaromatic fractions. [ABSTRACT FROM AUTHOR]

Aims: The protective role of fungal endophytes in plants under stress by hydrocarbons is yet poorly understood. The influence of the endophytic fungus Lewia sp. on growth and oxidative stress control in plants of Festuca arundinacea exposed to a hydrocarbon mixture (HCM) was evaluated. Methods: Plants of F. arundinacea were inoculated or not with Lewia sp. to establish endophytic association. After 15 days, the plant growth, oxidative stress, and activity of antioxidant enzymes were analyzed in associated and unassociated plants. Then, both groups of plants were exposed for 7 days to a HCM (800 mg kg) in a model soil. The effect of the HCM was assessed in the plants through the same variables as mentioned above. Results: Endophytic association was established after 15 days. The fungus enhanced plant growth, as well as HO and malondialdehyde concentration, and decreased glutathione S-transferase (GST) activity. Lewia sp. decreased the HO concentration in plants exposed to the HCM and increased the activity of superoxide dismutase and peroxidases, while significantly decreasing GST activity. Conclusions: This study demonstrates the positive role of Lewia sp. in promoting growth and alleviating oxidative stress in F. arundinacea exposed to hydrocarbons. [ABSTRACT FROM AUTHOR]

In the current investigation, Volatile Organic Compounds (VOCs) spontaneously emitted from the different organs ofInula viscosagrowing wild in Jordan were extracted by Solid Phase Micro Extraction (SPME) method and then analyzed using GC-MS technique. Oxygenated monoterpenes dominated roots emission (52.39%) while sesquiterpene hydrocarbons were the main class of compounds detected in the emission of the stems (60.05%). Leaves emission was characterized with high monoterpenoids content (oxygenated 24.34%, hydrocarbons 30.06%). The emission of the fully expanded flowers and flowering organs (receptacles, petals and pistils) was rich in oxygenated monoterpenes (51.96%, 46.94%, 45.45% and 53.13%, respectively). Flowering buds at the pre-flowering stage were rich in oxygenated sesquiterpenoids (40.02%). Principle Component Analysis (PCA) and Cluster Analysis (CA) analysis revealed that the emission profiles of differentI. viscosaorgans were classified into three clusters based on their chemical composition. In addition, the hydrodistilled essential oils obtained from the fresh leaves, pre-flowering buds and fully expanded flowers were dominated by oxygenated sesquiterpenoids (69.63, 92.75 and 76.70%, respectively). [ABSTRACT FROM PUBLISHER]

The essential oil composition of flowering aerial parts ofCentaurea imperialisHausskn. ex Bornm. (Asteraceae) from Iran was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) for the first time. Thirty seven constituents constituting 88.6% of the total oil were detected. The sesquiterpene hydrocarbons had the highest contribution. The main compounds were caryophyllene oxide (23.2%), germacrene D (19.7%) and β-caryophyllene (14.1%). [ABSTRACT FROM PUBLISHER]

Results from a determination of the saturated vapor pressures (SVPs) of 5-85 wt.% EtOH blends with various individual hydrocarbons are reported. A mathematical model for calculating the SVP of E30 bioethanol fuel is developed based on these results. Only the fuel hydrocarbon composition determined by chromatography can be used to calculate the SVP of bioethanol fuel by this model. [ABSTRACT FROM AUTHOR]

The activation of perfluoroalkyl iodides by the frustrated Lewis pair tris(pentafluorophenyl)borane and tri- tert-butylphosphine is described. By abstraction of both a fluorine and an iodine atom, an iodophosphonium fluoroborate salt is formed. In the presence of alkenes the corresponding iodoperfluoroalkylation products are generated regioselectively. First mechanistic investigations support a radical mechanism. [ABSTRACT FROM AUTHOR]

Purpose: Occupational exposure to combustion products rich in polycyclic aromatic hydrocarbons and particles is associated with an increased risk of lung cancer. This study aimed to evaluate whether the risk depended on the age at which the individuals were exposed. Methods: Data from 1042 lung cancer cases and 2364 frequency-matched population controls selected from all men aged 40-75 years residing in Stockholm County, Sweden, at any time between 1985 and 1990, included detailed questionnaire information on occupational, residential, and smoking history. Occupational exposures were assessed by an occupational hygienist, and exposure to air pollution from road traffic was estimated based on dispersion models. Results: We found that individuals exposed to combustion products in their twenties were at higher risk than those never exposed (adjusted OR = 1.46; 95 % CI 1.02, 2.10). The association was still evident after adjusting for a number of potential confounders, including lifetime cumulative exposure and latency. No clear association was found in those exposed at older ages. Conclusions: Exposure to combustion products at a young age was associated with elevated risk of lung cancer. Exposure-reduction programs should be aware of the susceptibility of the younger employees. [ABSTRACT FROM AUTHOR]

Background: Abnormalities in lipid and glucose metabolism are constantly observed in type 2 diabetes. However, these abnormalities can be ameliorated by polydatin. Considering the important role of proprotein convertase subtilisin/ kexin type 9 (PCSK9) in metabolic diseases, we explore the possible mechanism of polydatin on lipid and glucose metabolism through its effects on PCSK9. Methods: An insulin-resistant HepG2 cell model induced by palmitic acid (PA) and a db/db mice model were used to clarify the role of polydatin on lipid and glucose metabolism. Results: In insulin-resistant HepG2 cells, polydatin upregulated the protein levels of LDLR and GCK but repressed PCSK9 protein expression, besides, polydatin also inhibited the combination between PCSK9 and LDLR. Knockdown and overexpression experiments indicated that polydatin regulated LDLR and GCK expressions through PCSK9. In the db/db mice model, we found that polydatin markedly enhanced GCK and LDLR protein levels, and inhibited PCSK9 expression in the liver. Molecular docking assay was further performed to analyze the possible binding mode between polydatin and the PCSK9 crystal structure (PDB code: 2p4e), which indicated that steady hydrogen bonds formed between polydatin and PCSK9. Conclusions: Our study indicates that polydatin ameliorates lipid and glucose metabolism in type 2 diabetes mellitus by downregulating PCSK9. [ABSTRACT FROM AUTHOR]

The development of adverse outcome pathways (AOPs) is becoming a key component of twenty-first century toxicology. AOPs provide a conceptual framework that links the molecular initiating event to an adverse outcome through organized toxicological knowledge, bridging the gap from chemistry to toxicological effect. As nuclear receptors (NRs) play essential roles for many physiological processes within the body, they are used regularly as drug targets for therapies to treat many diseases including diabetes, cancer and neurodegenerative diseases. Due to the heightened development of NR ligands, there is increased need for the identification of related AOPs to facilitate their risk assessment. Many NR ligands have been linked specifically to steatosis. This article reviews and summarizes the role of NR and their importance with links between NR examined to identify plausible putative AOPs. The following NRs are shown to induce hepatic steatosis upon ligand binding: aryl hydrocarbon receptor, constitutive androstane receptor, oestrogen receptor, glucocorticoid receptor, farnesoid X receptor, liver X receptor, peroxisome proliferator-activated receptor, pregnane X receptor and the retinoic acid receptor. A preliminary, putative AOP was formed for NR binding linked to hepatic steatosis as the adverse outcome. [ABSTRACT FROM AUTHOR]

Background Occupational exposure to solvents may lead to neurotoxicity and sleep disturbances. We aimed to investigate the association of occupational exposure to petroleum-derived hydrocarbons with neurotoxicity and sleep disturbance symptoms. Methods We included male workers handling/distributing petroleum products (exposed, n = 250) and electricians (non-exposed, n = 250) from two companies in Tlemcen (Algeria). Neurotoxicity was evaluated with the Q-16 questionnaire, and sleep disturbances with the Epworth and the Berlin questionnaires. Multivariable Poisson regression models with robust error variances were applied obtaining risk ratios (RR) and their 95% confidence interval (CI). Results Overall, the prevalence of reported neurotoxicity and sleep disturbance symptoms was higher in exposed than in non-exposed workers. Significant adjusted associations were observed for neurotoxicity, snoring, and excessive sleepiness (RR = 2.2, CI: 1.7-2.8; RR = 1.4; CI: 1.1-1.7; RR = 1.3, CI: 1.2-1.5, respectively). No significant associations were observed with the Epworth score. Conclusions Our questionnaire-based cross-sectional study suggests that exposure to petroleum-derived hydrocarbons is associated with self-reported sleep disturbances and neurotoxicity symptoms. Am. J. Ind. Med. 59:129-136, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Male Neotropical orchid bees collect volatile chemicals from their environment and compose species-specific volatile signals, which are subsequently exposed during courtship display. These perfumes are hypothesized to serve as attractants and may play a role in female mate choice. Here, we investigated the potential of cuticular hydrocarbons as additional recognition cues. The cuticular hydrocarbons of males of 35 species belonging to four of the five extant euglossine bee genera consisted of aliphatic hydrocarbons ranging in chain lengths between 21 and 37 C-atoms in distinct compositions, especially between sympatric species of similar coloring and size, for all but one case. Cleptoparasitic Exaerete spp. had divergent profiles, with major compounds predominantly constituted by longer hydrocarbon chains (>30 C-atoms), which may represent an adaptation to the parasitic life history ('chemical insignificance'). Phylogenetic comparative analyses imply that the chemical profiles exhibited by Exaerete spp. are evolutionarily divergent from the rest of the group. Female hydrocarbon profiles were not identical to male profiles in the investigated species, with either partial or complete separation between sexes in multivariate analyses. Sexually dimorphic hydrocarbon profiles are assumed to be the basis for sex recognition in a number of insects, and thus may supplement the acquired perfume phenotypes in chemical information transfer. Overall, cuticular hydrocarbons meet the requirements to function as intraspecific and intersexual close range recognition signals; behavioral experiments are needed to determine their potential involvement in mate recognition. [ABSTRACT FROM AUTHOR]

In ant-aphid associations, many aphid species provide ants with honeydew and are tended by ants, whereas others are never tended and are frequently preyed upon by ants. In these relationships, ants must have the ability to discriminate among aphid species, with mutualistic aphids being accepted as partners rather than prey. Although ants reportedly use cuticular hydrocarbons (CHCs) of aphids to differentiate between mutualistic and non-mutualistic species, it is unclear whether the ability to recognize mutualistic aphid species as partners is innate or involves learning. Therefore, we tested whether aphid recognition by ants depends on learning, and whether the learning behavior is species-specific. When workers of the ant Tetramorium tsushimae had previously tended the cowpea aphid, Aphis craccivora, they were less aggressive toward this species. In addition, ants also reduced their aggressiveness toward another mutualistic aphid species, Aphis fabae, after tending A. craccivora, whereas ants remained aggressive toward the non-mutualistic aphid, Acyrthosiphon pisum, regardless of whether or not they had previous experience in tending A. craccivora. When ants were offered glass dummies treated with CHCs of these aphid species, ants that had tended A. craccivora displayed reduced aggression toward CHCs of A. craccivora and A. fabae. Chemical analyses showed the similarity of the CHC profiles between A. craccivora and A. fabae but not with A. pisum. These results suggest that aphid recognition of ants involves learning, and that the learning behavior may not be species-specific because of the similarity of CHCs between different aphid species with which they form mutualisms. [ABSTRACT FROM AUTHOR]

The parasitoid beetle Metoecus paradoxus frequently parasitizes colonies of the common wasp, Vespula vulgaris. It penetrates a host colony as a larva that attaches itself onto a foraging wasp's body and, once inside the nest, it feeds on a wasp larva inside a brood cell and then pupates. Avoiding detection by the wasp host is crucial when the beetle emerges. Here, we tested whether adult M. paradoxus beetles avoid detection by mimicking the cuticular hydrocarbon profile of their host. The beetles appear to be chemically adapted to their main host species, the common wasp, because they share more hydrocarbon compounds with it than they do with the related German wasp, V. germanica. In addition, aggression tests showed that adult beetles were attacked less by common wasp workers than by German wasp workers. Our results further indicated that the host-specific compounds were, at least partially, produced through recycling of the prey's hydrocarbons, and were not acquired through contact with the adult host. Moreover, the chemical profile of the beetles shows overproduction of the wasp queen pheromone, nonacosane (n-C), suggesting that beetles might mimic the queen's pheromonal bouquet. [ABSTRACT FROM AUTHOR]

The aquatic biota of the Arabian Gulf deals with exposure to chronic oil pollution, several constituents of which cause induction of Cytochrome P450 1A that serves as a biomarker of AhR ligand exposure. In this study, fluorescent aromatic compounds (FACs) in bile and 7-ethoxyresorufin-o-deethylase (EROD) catalytic activity were determined as a measure of exposure biomarkers in two fish species, yellow fin seabream ( Acanthopagrus latus ) and tonguesole ( Cynoglossus arel ) captured from Kuwait Bay and outside the Bay area. FACs in fish bile determined by using fixed-wavelength fluorescence (FF) showed high fluorescence ratios between FF290/335 and FF380/430 indicating predominant exposure to low molecular weight, naphthalene-rich petroleum products (375 ± 91.0 pg ml − 1 ). Exposures to benzo(a)pyrene-type high-molecular weight polycyclic aromatic hydrocarbons (PAHs) originating from burnt fuel were also present in appreciable concentration in the bile. The ratio of petrogenic to pyrogenic hydrocarbon was twofold higher in winter compared to summer months in both species. Seasonal effect on EROD was significant in tonguesole in Auha site ( P < 0.05); whereas seabream resisted seasonal change. Tonguesole is considered to be a suitable bioindicator of oil pollution in Kuwait Bay area. [ABSTRACT FROM AUTHOR]

The essential oils of the fresh flower, leaf, and stem of Sempervivum brevipilum Muirhead. (Crassulaceae) were isolated by hydrodistillation in a modified Clevenger-type apparatus, and characterized by GC-FID and GC-MS. A total of fifty, forty-three, and thirty-one compounds were identified, constituting over 92.6%, 92.6%, and 94.3% of oil composition of the flower, leaf, and stem of S. brevipilum, respectively. The chemical profile reveals the dominance of hydrocarbons (flower: 65.3%, leaf: 47.6%, stem: 71.1%). The major compounds of essential oils from S. brevipilum were tetracosane (20.2%) in flower, 1,2-diphenyl ethandione (16.1%) in leaf and docosane (30.5%) in stem. Monoterpene hydrocarbons were the major class of terpenoids in flower (2.2%) and in stem (1.8%), oxygenated diterpene was the major class of terpenoids in leaf (4.5%). Oxygenated monoterpenes were in minor amounts in all parts (flower: 0.3%, leaf: 0.7%, stem: 0.1%) of the plant. In addition, antimicrobial activities of the essential oils of S. brevipilum were investigated. The oils didn't show any antibacterial and antifungal activity against tested bacteria, but showed high antituberculostatic activity against Mycobacterium smegmatis. [ABSTRACT FROM AUTHOR]

More than 800 million L/d of hydrocarbon fuels is used to power cars, boats, and jet airplanes. The weekly consumption of these fuels necessarily puts the public at risk for repeated inhalation exposure. Recent studies showed that exposure to hydrocarbon jet fuel produces lethality in presynaptic sensory cells, leading to hearing loss, especially in the presence of noise. However, the effects of hydrocarbon jet fuel on the central auditory nervous system (CANS) have not received much attention. It is important to investigate the effects of hydrocarbons on the CANS in order to complete current knowledge regarding the ototoxic profile of such exposures. The objective of the current study was to determine whether inhalation exposure to hydrocarbon jet fuel might affect the functions of the CANS. Male Fischer 344 rats were randomly divided into four groups (control, noise, fuel, and fuel + noise). The structural and functional integrity of presynaptic sensory cells was determined in each group. Neurotransmission in both peripheral and central auditory pathways was simultaneously evaluated in order to identify and differentiate between peripheral and central dysfunctions. There were no detectable effects on pre- and postsynaptic peripheral functions. However, the responsiveness of the brain was significantly depressed and neural transmission time was markedly delayed. The development of CANS dysfunctions in the general public and the military due to cumulative exposure to hydrocarbon fuels may represent a significant but currently unrecognized public health issue. [ABSTRACT FROM AUTHOR]

Scorpions exhibit some of the lowest recorded water loss rates among terrestrial arthropods. Evaporative water loss to the surrounding environment occurs mainly through the integument, and thus its resistance to water loss has paramount significance for the ability of scorpions to tolerate extremely dry habitats. Cuticular hydrocarbons (HCs) deposited on the outer epicuticle play an important role in determining cuticular waterproofing, and seasonal variation in both cuticular HC quantity and composition has been shown to correlate with water loss rates. Precursor incorporation rates into cuticle HCs have been observed to be extremely low in scorpions compared with insects. We therefore used adult male Buthus occitanus (Buthidae) in order to test HC profile plasticity during acute exposure to 14 d and 28 d of experimental desiccation. Cuticular HC profile of hydrated scorpions was similar to that reported for several other scorpion species, consisting of similar fractions of n -alkanes and branched alkanes, with no evidence for unsaturation. Most abundant of the n -alkanes were n -heptacosane (C 27 ; 19 ± 2% of total HCs), n -nonacosane (C 29 ; 16 ± 1%) and n -hentriacontane (C 31 ; 11 ± 1%). Exposure to desiccation stress resulted in a significant increase in the total amount of extracted HCs, and in the relative abundance of branched alkanes at the expense of n -alkanes. Together with an increase in HC chain lengths, these changes mimic previously-reported seasonal variation among freshly-collected specimens. This indicates that scorpions respond to water shortage by regulating the properties of their passive integumental barrier to water loss. [ABSTRACT FROM AUTHOR]

Background There is no consensus on the association between exposure to hydrocarbons and the risk of Parkinson's disease (PD). We conducted a systematic review and meta-analysis to summarise the epidemiological evidence and included a new large case-control study. Methods Data were extracted following a predefined protocol. Risk estimates regarding the association between hydrocarbon exposure and PD were consolidated to produce a summary odds ratio (OR), 95% confidence intervals (CI), and p-value. In our case-control study, 1463 PD patients and 685 controls were recruited from clinical trials and completed a structured questionnaire describing their previous working exposure to hydrocarbons and other demographic measures. The association between exposure to hydrocarbons and risk of PD was evaluated using logistic regression. Results The systematic search identified 13 case-control studies matching the inclusion criteria. The meta-analysis included 3020 PD cases and 6494 controls. The summary OR was 1.32 (95% CI 1.08–1.62, p = 0.006) for hydrocarbon exposure (ever versus never). In the PD GEN study, occupational exposure to hydrocarbons significantly increased the risk of PD (OR = 1.61; 95% CI 1.10–2.36, p = 0.014), and risk dose-dependently increased for subjects exposed greater than 10 years compared to subjects never exposed (OR = 2.19; 95% CI 1.13–4.26, p = 0.021). The addition of PD GEN data increased the total numbers to 4483 PD cases and 7179 controls and strengthened the significant association (summary OR = 1.36; 95% CI 1.13–1.63, p = 0.001). Conclusions This systematic review supports a positive association between hydrocarbon exposure and PD. Data from prospective studies are required to reinforce the relationship between hydrocarbon exposure and PD. [ABSTRACT FROM AUTHOR]

Produced water is the main discharge stream from oil and gas production. For offshore activities this water is usually discharged to the marine environment. Produced water contains traces of hydrocarbons such as polycyclic aromatic hydrocarbons as well as alkylphenols, which are relatively resistant to biodegradation and have been reported to cause adverse effects to marine organisms in laboratory studies. For management of produced water, risk-based tools have been developed using toxicity data for mainly non-Arctic species. Reliable risk assessment approaches for Arctic environments are requested to manage potential impacts of produced water associated with increased oil and gas activities in Arctic regions. In order to assess the applicability of existing risk tools for Arctic areas, basic knowledge on the sensitivity of Arctic species has to be developed. In the present study, acute and chronic toxicity of artificial produced water for 6 Arctic and 6 temperate species was experimentally tested and evaluated. The hazardous concentrations affecting 5% and 50% of the species were calculated from species sensitivity distribution curves. Hazardous concentrations were compared to elucidate whether temperate toxicity data used in risk assessment are sufficiently representative for Arctic species. From the study it can be concluded that hazardous concentration derived from individual species' toxicity data of temperate and Arctic species are comparable. However, the manner in which Arctic and non-Arctic populations and communities respond to exposure levels above established thresholds remains to be investigated. Hence, responses at higher levels of biological organization should be studied to reveal potential differences in sensitivities to produced water between Arctic and non-Arctic ecosystems. [ABSTRACT FROM AUTHOR]

In the present study, the polycyclic aromatic hydrocarbons (PAHs) in indoor dust and outdoor dust including road and window dust around the traffic road in Hunan Province, China, were sampled and detected. The ∑PAHs in indoor dust ranged from 5007-24,236 ng g, with a median of 14,049 ng g. The ∑PAHs in road dust ranged from 3644-12,875 ng g, with a median of 10,559 ng g. The ∑PAHs in window dust ranged from 803-12,590 ng g, with a median of 5459 ng g. Similar pattern of PAHs was observed in road and window dust except in H3W and H4W samples, which was dominated by naphthalene (Nap), benzo( b+ k)fluoranthene (B( b+ k)F), phenanthrene (Phe), and fluorine (Fle). Indoor dust showed slightly different PAHs profiles, which was dominated by Nap, fluoranthene (Fla) and Phe. Risk assessment indicated that dermal contact and dust ingestion exposure pathways were more important than the inhalation pathway. Cancer risk of PAHs via dust varied from 2.73 × 10-8.04 × 10, with a median of 2.06 × 10 for children, and from 2 × 10-5.89 × 10, with a median of 1.52 × 10 for adult. Probit model showed that 76 and 71 % of samples in the sampling area would result in the risk of children and adult exposure to PAHs via dust higher than the acceptable level (1 × 10), respectively. [ABSTRACT FROM AUTHOR]

This paper deals with the migration of selected hydrocarbon contaminants, namely mineral oil hydrocarbons (MOH), diisopropyl naphthalenes (DIPN) and polyalphaolefins (PAO) from adhesives into dry semolina and egg pasta packaged in direct contact with recycled paperboard. Migration was monitored during its shelf life (for up to two years) simulating storage in a supermarket (packs on shelves) and conditions preventing exchange with the surrounding environment (packs wrapped in aluminium foil). Migration from the secondary packaging (transport boxes of corrugated board) was also studied for semolina pasta. After 24 months of exposure, semolina pasta stored on shelves reached 3.2 and 0.6 mg kg−1of MOSH and MOAH, respectively, Migration from the adhesives used to close the boxes and from the transport boxes contributed about 30% and 25% of the total contamination, respectively. The highest contamination levels (14.5 and 2.0 mg kg−1of MOSH and MOAH, respectively, after 24 months) were found in egg pasta stored on shelves (no adhesives), and seemed due to the highest contribution from the external environment. [ABSTRACT FROM AUTHOR]

The effects of dietary supplementation with natural honey on haematological profile, blood sugar and final body weight of rats fed diets contaminated with hydrocarbon petroleum products (gasoline and kerosene) were evaluated in this study. There was a significant (P<0.05) decrease in haemoglobin (Hb) content, red blood cell (RBC) count, packed cell volume (PCV) and platelet count but a significant increase in white blood cell count (WBCC) in rats fed gasoline and kerosene contaminated diet compared to the control rats. Gasoline and kerosene contaminated diet also resulted in significant (P<0.05) decrease in blood sugar and final body weight of rats as compared to the control. Supplementation of diet and post treatment with natural honey significantly (P<0.05) restored Hb content, RBC, PCV, platelet and WBCC close to control values. Although supplementation of gasoline and kerosene contaminated diet did not substantially improve the final body weight and percentage increase in weight, post treatment with natural honey significantly (P<0.05) improved the blood glucose, final body weight and percentage increase in weight of rats compared to rats fed gasoline and kerosene contaminated diet only. These findings indicate that natural honey has ameliorative effect on gasoline and kerosene induced haematotoxicity, hypoglycaemia and weight loss. [ABSTRACT FROM AUTHOR]

Although planktonic protozoans are likely to interact with dispersed crude oil after a spill, protozoan-mediated processes affecting crude oil pollution in the sea are still not well known. Here, we present the first evidence of ingestion and defecation of physically or chemically dispersed crude oil droplets (1-86 μm in diameter) by heterotrophic dinoflagellates, major components of marine planktonic food webs. At a crude oil concentration commonly found after an oil spill (1 μL L-1), the heterotrophic dinoflagellates Noctiluca scintillans and Gyrodinium spirale grew and ingested ~0.37 μg-oil μg-Cdino-1 d-1, which could represent ~17% to 100% of dispersed oil in surface waters when heterotrophic dinoflagellates are abundant or bloom. Egestion of faecal pellets containing crude oil by heterotrophic dinoflagellates could contribute to the sinking and flux of toxic petroleum hydrocarbons in coastal waters. Our study indicates that crude oil ingestion by heterotrophic dinoflagellates is a noteworthy route by which petroleum enters marine food webs and a previously overlooked biological process influencing the fate of crude oil in the sea after spills. [ABSTRACT FROM AUTHOR]

In most species of social insect the queen signals her presence to her workers via pheromones. Worker responses to queen pheromones include retinue formation around the queen, inhibition of queen cell production and suppression of worker ovary activation. Here we show that the queen signal of the Brazilian stingless bee Friesella schrottkyi is a mixture of cuticular hydrocarbons. Stingless bees are therefore similar to ants, wasps and bumble bees, but differ from honey bees in which the queen's signal mostly comprises volatile compounds originating from the mandibular glands. This shows that cuticular hydrocarbons have independently evolved as the queen's signal across multiple taxa, and that the honey bees are exceptional. We also report the distribution of four active queen-signal compounds by Matrix-assisted laser desorption/ ionization (MALDI) imaging. The results indicate a relationship between the behavior of workers towards the queen and the likely site of secretion of the queen's pheromones. [ABSTRACT FROM AUTHOR]

Dearomatized hydrocarbon solvents in the C9–C14 aliphatic carbon number range were developed as alternatives to traditional solvents such as mineral spirits, but with lower aromatic content. Previous subchronic toxicity studies (both published and unpublished) have shown minimal to no systemic effects with exposure to dearomatized solvents, with the exception of rat-specific renal effects that have no relevance to humans. In this study, Sprague–Dawley rats were exposed to 0, 500, 2500 and 5000 mg/kg/day of a C10–C13 dearomatized solvent for 90 days by oral gavage. Liver enlargement and centrilobular hypertrophy were observed in all treated groups but were considered adaptive consequences of hydrocarbon-induced microsomal enzyme induction. Clinical chemistry data showed elevations of alanine aminotransferase (ALT), gamma glutamyltransferase (GGT) and total bilirubin in mid (ALT alone) and high dose groups, suggesting potential hepatobiliary effects with high dose exposure. Increased absolute kidney weight changes were restricted to male rats and associated with renal lesions indicative of alpha-2u globulin-mediated nephropathy. One limitation of the NOAEL/LOAEL approach in selecting points of departure for exposure limits is its dependence on dose selection/study design. Hence, a more robust approach that incorporates all data points on the dose–response curve, such as bench mark modeling, is preferred. Overall, benchmark dose analysis estimated a BMDL of 1857 mg/kg/day based on increased serum ALT. This value is consistent with studies of similar hydrocarbon substances showing a lack of systemic effects at doses up to 1000 mg/kg/day in the same rat strain. [ABSTRACT FROM AUTHOR]

The ligand-activated nuclear receptor AhR (aryl hydrocarbon receptor) mediates the response of hepatocytes to various exogenous compounds. AhR is classically activated by planar, aromatic hydrocarbons, but also by other, structurally rather unrelated compounds. Recent data show that the canonical Wnt/β-catenin signaling pathway is also involved in the regulation of hepatic zonal gene expression and drug metabolism in mammalian liver. Previous studies indicate that the loss of β-catenin in hepatocytes diminishes the response to the AhR agonists 3-methylcholanthrene (3MC) in vivo and to 2,3,7,8-tetrachlorodibenzo-[ p ]-dioxin in vitro . The knockout of β-catenin also impairs the zonal pattern of AhR target gene induction by 3MC. However, it is presently unknown whether the chemical nature of the AhR agonist influences the AhR/β-catenin interaction. Moreover, no information is available about the dose–response curves of AhR activation in the absence or presence of Wnt/β-catenin signaling. In the present study, we have analyzed AhR-dependent responses to different concentrations of structurally unrelated AhR agonists in vivo and in vitro . The results demonstrate that β-catenin is essential to obtain the maximum AhR response. Moreover, using transgenic mouse models which allow for the ablation of β-catenin at different age of mice, we demonstrate that the presence of β-catenin, not postnatal developmental effects in β-catenin-deficient livers, is responsible for the observed interplay of β-catenin and the AhR. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are found in ambient aerosols and particulate matter. Experimental studies have shown that PAHs and related chemicals can induce toxicological effects. The present study aimed to investigate the effects of PAHs and their derivatives on the respiratory and immune systems and the underlying mechanisms. The human bronchial epithelial cell line BEAS-2B was exposed to PAHs and their derivatives, and the cytotoxicity and proinflammatory protein expression were then investigated. A cytotoxic effect was observed in BEAS-2B exposed to PAH derivatives such as naphthoquinone (NQ), phenanthrenequinone (PQ), 1-nitropyrene (1-NP), and 1-aminopyrene (1-AP). In addition, 1,2-NQ and 9,10-PQ showed more effective cytotoxicity than 1,4-NQ and 1,4-PQ, respectively. Pyrene showed a weak cytotoxic effect. On the other hand, naphthalene and phenanthrene showed no significant effects. Pyrene, 1-NP, and 1-AP also increased intercellular adhesion molecule-1 expression and interleukin-6 production in BEAS-2B. The increase was partly suppressed by protein kinase inhibitors such as the epidermal growth factor receptor-selective tyrosine kinase inhibitor and nuclear receptor antagonists such as the thyroid hormone receptor antagonist. The present study suggests that the toxicological effects of chemicals may be related to the different activities resulting from their structures, such as numbers of benzene rings and functional groups. Furthermore, the chemical-induced increase in proinflammatory protein expression in bronchial epithelial cells was possibly a result of the activation of protein kinase pathways and nuclear receptors. The increase may partly contribute to the adverse health effects of atmospheric PAHs. [ABSTRACT FROM AUTHOR]

Products of a hydrocarbon fire accident have both chronic and acute health effects. They cause respiratory issues to lung cancer. While fire is the most frequent phenomenon among the offshore accidents, predicting the contaminants' concentration and their behavior are key issues. Safety measures design, such as ventilation and emergency routes based only on predicted contaminants' concentration seems not to be the best approach. In a combustion process, various harmful substances are produced and their concentration cannot be added. The time duration that any individual spends in different locations of an offshore installation also varies significantly. A risk-based approach considers the duration a person is exposed to contaminants at various locations and also evaluates the hazardous impacts. A risk-based approach has also an additivity characteristic which helps to assess overall risk. Through the current study, an approach is proposed to be used for risk assessment of combustion products dispersion phenomenon in a confined or semi-confined facility. Considering CO, NO2 and CH4 as the contaminants of concern, the dispersion of the substances over the layout of the facility after a LNG fire is modeled. Considering different exposure times for three major parts of the facility including the processing area, office area and the accommodation module, the risk contours of CO, NO2 and CH4 over the entire facility are developed. The additivity characteristic of the risk-based approach was used to calculate the overall risk. The proposed approach helps to better design safety measures to minimize the impacts and effective emergency evacuation planning. [ABSTRACT FROM AUTHOR]