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The bottom‐up synthesis of carbon nanotubes (CNTs) is a long‐standing goal in synthetic chemistry. Producing CNTs with defined lengths and diameters would render these materials and thus their fascinating properties accessible in a controlled way. Inspired by a recently reported synthesis of armchair graphene sheets that relied on a benzannulation and Scholl oxidation of a poly(p‐phenylene ethynylene), the same strategy is applied on a cyclic substrate with a short, but well defined CNT as target structure. Herein we report the synthesis of a derivatized [12]cycloparaphenylene acetylene ([12]CPPA) that was accessible employing a Sonogashira macrocyclization. The obtained macrocycle is the largest [n]CPPA reported to date and displays bright turquoise fluorescence with a large quantum yield of 77 %. The [12]CPPA can be transformed by a 12‐fold benzannulation that converts each alkyne to a naphthalene and therefore allows formation of an armchair [12,12]CNT precursor. The final 72‐fold Scholl oxidation to the [12,12]CNT turned out to be challenging and its optimization requires an improved synthetic strategy to produce large quantities of the final precursor. The developed approach poses a potential break through strategy for the production of CNTs and certainly incentivizes synthetic chemists to apply the same methodology for various conjugated macrocycles. [ABSTRACT FROM AUTHOR]

Alcaligens faecalis strain ULAG3AF was isolated from the Lagos Lagoon, an estuarine environment. The aim of the study was to investigate the biosurfactant production potentials of this organism and explore the antimicrobial potential of the biosurfactant. The bacterial isolate was screened for its biosurfactants production potentials using the drop collapse, oil displacement tests and emulsification index. The strain was cultivated in an enrichment medium, Bushnell Haas Medium, supplemented with 1%, 2%, 3% and 4% v/v o o o o o spent engine oil and grown at different temperatures including 15 C, 25 C, 30 C, 35 C and 40 C and salinity (10 mg/l, 20 mg/l, 30 mg/l and 40 mg/l of NaCl). The optimisation process involved analysing the effect of substrate concentration, temperature, and salinity on biosurfactant production by the bacterium using the onevariable-at-a-time (OVAT) approach. Gas Chromatography and Mass Spectrometry (GC-MS) and emulsification index were used to determine the rate of hydrocarbon degradation and the concentration of biosurfactant produced by the organism respectively. The bacterium demonstrated the ability to biodegrade different polyaromatic hydrocarbon components of spent engine oil and produced biosurfactants with an emulsifying index of 80.9% when cultivated in a medium containing 2% v/v of spent engine oil, 2% salinity (20 o mg/l of NaCl) and a temperature of 40 C after 7 days. The biosurfactant produced was a glycolipid with antimicrobial activities against Klebsiella pneumonia, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

This study focuses on the development of regiospecific hydroarylation polyaddition of naphthalene‐ and carbazole‐based monomers with diynes under mild reaction conditions at room temperature. A 1‐pyrazole substituent serves as an appropriate directing group for a Co‐catalyst to efficiently activate the C–H bonds of generally inactive six‐membered aromatic hydrocarbons. The 1‐pyrazole groups in 2,6‐di(1‐pyrazolyl)naphthalene adopt planar conformations and act as directing groups, resulting in a smooth hydroarylation reaction. In contrast, the reaction with 1,5‐di(1‐pyrazolyl)naphthalene do not proceed. The polyaddition reaction of 2,6‐di(1‐pyrazolyl)naphthalene selectively proceeds at 3,7‐positions under mild reaction conditions at 30 °C, and yields corresponding poly(arylenevinylene) (PAV) with high molecular weight. This molecular design is also applicable to the hydroarylation polyaddition of carbazole; the polyaddition reaction of 9‐(2‐ethylhexyl)‐3,6‐di(1‐pyrazolyl)carbazole selectively occurred at 2,7‐positions. The optical and electronic properties of the synthesized compounds are evaluated. The obtained PAVs serve as an emitting material in organic light‐emitting diode (OLED). This study aims to develop a Co‐catalyzed hydroarylation polyaddition via C–H activation of generally inactive polyaromatic hydrocarbons (PAHs) under mild conditions. [ABSTRACT FROM AUTHOR]

In coal gasification, soot forms from volatile matter (VM) and it influences the gasification efficiency. Recently, biomass or plastic wastes with higher VM than coal are used for gasification processes and the importance of soot is increasing. For predicting soot formation, elementary step models are often used. However, defining main reaction paths is difficult because the models include huge species and reactions. In this study, the polyaromatic hydrocarbon formation path was analyzed via an elementary step-like model with 257 species and 1107 reactions to understand soot formation. The main reaction paths were extracted. Initially, 257 species were classified into non-aromatic species, one-ring, two-ring, and three- or more-ring aromatics. Ten species in each group with high maximum concentrations were considered as the major species. The reactions were extracted as follows: extracting reactions according to their contribution to the major species mass balance; adding fast reactions; and identifying the main reaction path. Consequently, the main reaction path extracted (MRE) model for the combustor condition was reduced to under 100 reactions for two kinds of conditions. Simulation of coal gasification reaction with the MRE model successfully described soot formation behavior in experiments with a drop tube furnace.

Introduction: Polyaromatic hydrocarbons (PAHs) are considered as redox active environmental toxicants inducing oxidative stress (OS) mediated injury to cells. Oxidative predominance is reported in 30%-80% of idiopathic male infertility (IMI) patients. Hence, this work aims to unravel correlation, if any, between seminal PAH exposome and sperm function in IMI patients through a proteomic approach. Methods: Seminal PAH exposome was analyzed in 43 fertile donors and 60 IMI patients by HPLC and receiver operating characteristic (ROC) curve was applied to find out the cut-off limits. Spermatozoa proteome was analyzed by label free liquid chromatography mass spectroscopy (LC-MS/MS) followed by molecular pathway analysis using bioinformatic tools. Validation of key proteins' expression and protein oxidative modifications were analyzed by western blot. Results and discussion: Of the 16 standards toxic PAH, 13 were detected in semen. Impact of the different PAHs on fertility are Anthracene < benzo (a) pyrene < benzo [b] fluoranthene < Fluoranthene < benzo (a) anthracene ROC). Benzo [a] pyrene is invariably present in all infertile patients while naphthalene is present in both groups. Of the total 773 detected proteins (Control: 631 and PAH: 717); 71 were differentially expressed (13 underexpressed, 58 overexpressed) in IMI patients. Enrichment analysis revealed them to be involved in mitochondrial dysfunction and oxidative phosphorylation, DNA damage, Aryl hydrocarbon receptor (AHR) signaling, xenobiotic metabolism and induction of NRF-2 mediated OS response. Increased 4-hydroxynonenal and nitrosylated protein adduct formation, and declined antioxidant defense validates induction of OS. Increased GSH/GSSG ratio in patients may be an adaptive response for PAH metabolism via conjugation as evidenced by over-expression of AHR and Heat shock protein 90 beta (HSP90β) in patients. Seminal PAH concentrations, particularly benzo (a) pyrene can be used as a marker to distinguish IMI from fertile ones with 66.67% sensitivity and 100% specificity (95% confidence interval) along with oxidative protein modification and expression of AHR and HSP90β.

Energy-based surgical instruments produce surgical smoke, which contains harmful byproducts, such as polycyclic aromatic hydrocarbons, volatile organic compounds, particulate matter, and viable microorganisms. The research setting has shifted from the laboratory to the operating room. However, significant heterogeneity in the methods of detection and placement of samplers, diversity in the tissue operated on, and types of surgeries tested has resulted in variability in detected levels and composition of surgical smoke. State regulation limiting surgical smoke exposure through local evacuators is expanding but has yet to reach the national regulatory level. However, most studies have not shown levels above standard established limits but relatively short bursts of high concentrations of these harmful by-products. This review highlights the limitations of the current research and unsupported conclusions while also suggesting further areas of interest that need more focus to improve Occupational Safety and Health Administration guidelines. [ABSTRACT FROM AUTHOR]

Air quality represents one of the most important parameters determining indoor microclimate and human comfort. Thus, the current study reports a comprehensive study on the dominant sources, organic compositions, and potential health impacts of the polyaromatic hydrocarbons (PAHs) in the atmospheric particle matters (PMs) ranging from 2.5 µm (PM2.5) to 10 µm (PM10) size in the rural and urban regions of western (Jeddah city) Saudi Arabia collected over 1 year between 2014 and 2015. The levels of PAHs in two locations namely Obhur (Urban) and Hada Alsham (Rural) were monitored over 1 year (2014 and 2015) using the gas chromatography coupled mass spectrometry. The level of ƩPAHs in Obhur (819.25 ng/m3) has a significantly high concentration of PAHs compared to Hada Alsham (Rural) (675.26 ng/m3). Indeno(1,2,3-CD)pyrene was the major contributor with an average value of 215.66 ng/m3 followed by benzo[k]fluranthene with a concentration of 150.68 ng/m3, respectively. The major contributors were indeno[1,2,3-cd]pyrene, benzo[k]fluranthene, dibenzo[a,h]anthracene, benzo[g,h]perylene, and benzo[b]fluranthene are the major contributors with contributing percentages of 26.32, 18.39, 9.07, and 8.29%, respectively. The rest of all compounds were below 4%. The highest concentrations of PAHs in Obhur (1836.99 ng/m3) and in Hada Alsham (1107.40 ng/m3) were observed in winter in January 2014. PAHs with 4–6 aromatic ring components are primarily emitted by high temperature combustion. The average values for the BaA/(BaA + Chr) and Flt/(Flt + Pyr) ratios at Obhur were found 0.58 and 0.43 and at Hada Alsham were found 0.63 and 0.38, respectively, indicating that coal/biomass burning is the major source of PAHs. Hada Alsham (rural area), the transportation system, is a significant contributor to the observed PAHs. These results reflect Saudi Arabia’s traffic load in both rural and urban areas. On road sites, the impact of petroleum combustion and vehicular emissions was also identified. The sum of the incremental lifetime cancer risk (ILCR) for all congeners for infants along the Obhur location was 2.13 × 10−6 and 1.38 × 10−6, respectively. ILCR values were less than 1.0 × 10−4, implying that PAH exposure posed an acceptable potential cancer risk in this study. Various local emission sources contributed more PAHs in many Saudi urban areas, increasing the risk of lung cancer, and the health risk. PAHs have an associated large surface area and are capable of deposition in the respiratory system with high efficiency. The total health risk assessment study also helps in alarming the toxicity at both the locations.

Rapid urbanization has resulted in the discharge of large amounts of polyaromatic hydrocarbons (PAH) into the environment. Due to PAH-associated health hazards, their presence in water bodies has attracted increasing concern worldwide. Hence, it is necessary to device, new, efficient, and cost-effective technologies for their removal. The present work reports the fabrication of a novel chitosan linked activated carbon-nano-bentonite composite (AC-NB-C) membrane removal of acenaphthene (ACE) and naphthalene (NAP) from aqueous solutions containing both PAHs individually as well as a mixture (MP). The formulated membrane was characterized using SEM, TEM, EDS, FT-IR, XRD, and BET. The PAH removal efficiency of the membrane was evaluated in terms of varying process parameters such as initial PAH concentration, pH, and feed pressure. Process optimization was conducted using the central composite design (CCD) feature of response surface methodology (RSM). Reusability potential and antifouling property of the membrane was also evaluated. Under optimized conditions, the AC-NB-C membrane demonstrated a mixed PAH (MP) rejection of approximately 99.3%. The BET surface area and total pore volume of the membrane were observed to be 482.07 m2g–1 and 0.251 cm3g–1 respectively. The FT-IR analysis suggested π-π interaction and H-bonding as possible mechanisms guiding PAH uptake. A 4.9% reduction in flux ratio indicated good antifouling potential of the AC-NB-C membranes. Moreover, the membrane could be regenerated and reused for 7 consecutive cycles of filtration without any decline in its efficiency. Also, the optimum membrane performance recorded at pH 6 established its immense potential for large-scale treatment of municipal wastewater whose pH values are normally between 6 and 8. [ABSTRACT FROM AUTHOR]

In this review, two important environmental pollutants have been considered for its potential remediation using microbial-derived nano-enzymes. Firstly, polyaromatic hydrocarbons (PAHs) are one of the major industrial contaminants in the environment due to their ubiquitous occurrence, toxicity, and proclivity for bioaccumulation. Secondly, biofouling due to biofilm-forming organisms that impact tremendous economic and environmental consequences in many industries, especially marine vessels where it causes an increase in hydrodynamic drag, which results in a loss of ship speed at constant power or a power increase to maintain the same speed with higher fuel consumption and emissions into the atmosphere, particularly Green House Gases (GHGs). Among the remediation strategies, biological routes are found to be promising, efficient, and sustainable. Natural ligninolytic enzymes such as MnP, LiP, laccase, peroxidases, and polysaccharide and protein degradative enzymes are found to be highly efficient for PAH degradation and antifouling respectively. However, large-scale usage of these enzymes is difficult due to various reasons like their poor stability, adaptation, and high-cost production of these enzymes. In recent years, the use of nanoparticles, particularly nano-enzymes, is found to be an innovative and synergistic approach to detoxify contaminated areas with concomitant maintenance of enzyme stability. [ABSTRACT FROM AUTHOR]

Crude oil and polycyclic aromatic hydrocarbon (PAH) exposure in early life stage fish has been well-characterized to induce phenotypic malformations such as altered heart development and other morphological impacts. The effects of chemical oil dispersants on toxicity are more controversial. To better understand how chemical dispersion of oil can impact toxicity in pelagic fish, embryos of mahi-mahi (Coryphaena hippurus) were exposed to three concentrations of the chemical dispersant Corexit 9500A, or Corexit 9500A-oil mixtures (chemically enhanced water accommodated fractions: CEWAF) of Deepwater Horizon crude oil for 48 h. RNA sequencing, gene ontology enrichment, and phenotypic measurements were conducted to assess toxicity. Exposure to Corexit 9500A altered expression of less than 50 genes at all concentrations (2.5, 5, and 10 mg/L nominal concentration) and did not induce acute mortality or phenotypic malformations, corroborating other studies showing minimal effects of Corexit 9500A on developing mahi-mahi embryos. CEWAF preparations contained environmentally relevant ∑PAH concentrations ranging from 1.4 to 3.1 μg/L and similarly did not alter larval morphology. Differentially expressed genes and significantly altered pathways related to cardiotoxicity, visual impairments, and Ca2+ homeostasis reinforced previous work that expression of genes associated with the heart and eye are highly sensitive molecular endpoints in oil-exposed early life stage fish. Differential expression and gene ontology pathways were similar across the three CEWAF treatments, indicating that increased chemical dispersion did not alter molecular outcomes within the range tested here. In addition, significant sublethal molecular responses occurred in the absence of observable phenotypic changes to the heart, indicating that effects of oil on early life stage fish may not be completely dependent on cardiac function.

The co-contamination of soils with heavy metals and organic contaminants is a problem that requires a different and innovative approach to remediate these kinds of sites. The different nature of these two contaminant groups makes the problem complicated. Recently, zero-valent iron nanoparticles (nZVI) application has been integrated with bioremediation to be used for the remediation of halogenated organics. However, the use of this process for the remediation of co-contaminated soils has not been investigated. In this study, nZVI application integrated with bioremediation approaches (bioattenuation and biostimulation) was applied to Pb and naphthalene spiked soils in laboratory-scale reactors. Soil Pb fractions and naphthalene concentrations were monitored for 90 days. The nZVI decreased the mobility and bioavailability of Pb significantly by reducing exchangeable and carbonate bound fractions from 66.2 % to 25.8 – 37.2 % range. The nZVI also caused naphthalene degradation in the range of 38.8 – 58.5 %. Significant biodegradation of naphthalene occurred at samples subjected to nZVI and biostimulation. The highest overall naphthalene degradation (76.7 %) was obtained from the nZVI application which was integrated with biostimulation.

This study estimated polyaromatic hydrocarbons levels and bacterial load on soil after thirty (30) days consistent disposal of untreated hairdressing saloon effluent in Lokoja, Kogi State, Nigeria using standard methods. After 30 days of pollution, the topsoil was collected from the height of 0-5cm, the midsoil (12-17cm) and the subsoil (25-30cm). A non-polluted soil sample was also collected which served as the control for this experiment. The total heterotrophic bacteria count was determined. Toxicity analysis was carried out to determine the effect of the effluent on soil bacteria. The soil samples were also analyzed for the presence of polyaromatic hydrocarbon using gas chromatography with mass spectrometry. The polyaromatic hydrocarbon (PAHs) detected in the test soil sample were 45.02ng/g Biphenyl, 28.23ng/g Benzo[a]pyrene, 12.05ng/g Anthracene, 23.00ng/g, and 5.07ng/g Phenanthrene. 2.01ng/g of Biphenyl was detected in the control garden soil. Bacteria counts from the contaminated soil range from 1.0 x102± 1.10 to 4.0 x 102 ± 0.11. The counts from the control soil sample range from 2.0 x103± 0.20 to 8.2 x103 ± 0.20. The control soil sample had a higher value compared to the test soil samples. Bacteria species isolated from these soil samples were: Serretia sp., Klebsiella sp., Escherichia coli, Pseudomonas sp., and Staphylococcus sp. with Pseudomonas sp. and Staphylococcus sp. showing increased percentage occurrence. The acute and chronic toxicity test showed a decline in the bacterial count, which could have occurred due to the presence of PAHs from Saloon effluent. It was observed that a constant release of PAHs into the soil poses serious threat to the survival of soil bacteria, and can alter the various beneficial roles these bacteria play in the soil ecosystem. [ABSTRACT FROM AUTHOR]

Background. In developing and under-developed countries, charcoal production predisposes workers to charcoal dust. This is a common occurrence as workers in this field are not properly protected and as such are exposed to charcoal dust through inhalation and skin contact. Charcoal comprises many components such as polycyclic aromatic hydrocarbons (PAHs). Due to the possible health risk associated with such exposure, this study was designed to determine the effects of charcoal powder of particle size 125 µm - 150 µm on certain biomarkers in male albino rats. Albino rats were used because of their similar physiology to humans. Materials and Methods. 20 albino rats weighing between 250 g and 300 g were used for this study; they were randomly distributed in 4 groups (5 rats each) and the charcoal powder was incorporated into their feed at different percentages; control, group 1 (10 % charcoal), group 2 (30 % charcoal) and group 3 (charcoal powder bedding) for 50 days. Using standard procedures and methods, the following parameters were tested: Hematological parameters, semen parameters, liver enzymes, renal function, hormones and lung histology. Results. The results indicated a decrease in the level of liver enzymes AST (IU/L) and ALT (IU/L) in group 1, group 2 and group 3 when compared to the control with the lowest value of 48.75 IU/L and 11.50 IU/L respectively recorded in group 2. Prolactin (mIU/L) had mean values of 1.73, 1.30 and 1.83 in group 1, group 2 and group 3 respectively while the control was 2.10. Testosterone (nmol/L) had a mean value of 1.18, 0.53 and 0.25 in group 1, group 2 and group 3, respectively, while the control was 0.90 with a significant difference (P

Burkholderia cepacia BCTT , isolated from chronically polluted soil in Trinidad, shows a capacity to survive in crude oil as a sole carbon source. Here, we report its high-quality draft genome sequence and highlight those pathways and genes involved in xenobiotic degradation. These data give a clearer insight into this organism's biotechnological potential., Competing Interests: The authors declare no conflict of interest.

Breast cancer (BC) is a foremost type of cancer in women globally with an increased mortality rate in developing countries. Information regarding hereditary factors, lifestyle, work environment, food habits, and personal history could be useful in diagnosing breast cancer. Among such food habits, the reuse of edible oil for preparing food is a common practice in any developing country. The repeated heating of oils enhances the oxidative degradation of oil to produce polyaromatic hydrocarbons (PAH) which could disrupt the redox balance and generate reactive oxygen species. These reactive toxic intermediates can lead to BRCA1 mutations that are responsible for breast cancer. Mutations in DNA are the main cause for the conversion of proto-oncogenes into oncogenes which leads to change in expression and an increase in cell proliferation wherein a normal cell gets transformed into a malignant neoplastic cell. This review summarizes the possible mechanism involved in the induction of breast cancer due to repeated heating of edible. [ABSTRACT FROM AUTHOR]

Herein, we present a molecular design of chrysene‐based deep‐blue emissive materials (TC, TpPC, TpXC, and TmPC), in which chrysene as a core is functionalized with different triphenylamine moieties to realize a fine‐tuning deep‐blue fluorescence with superior electroluminescent (EL) performance. The photophysical analyses and density functional theory (DFT) calculations disclose that TC, TpPC, and TpXC possess HLCT characteristics with intense deep‐blue emission in the solid‐state, good hole‐transporting ability, and high thermal and electrochemical stabilities. They are successfully employed as non‐doped emitters in simple structured OLEDs (ITO/PEDOT : PSS : NF/emitter/TPBi/LiF : Al). In particular, TC‐based device emits a deep‐blue light with an emission peak at 446 nm and CIE color coordinates of (0.148, 0.096), a maximum external quantum efficiency (EQEmax) of 4.31%, and a low turn‐on voltage of 2.8 V. [ABSTRACT FROM AUTHOR]

Ultraviolet resonance Raman (UVRR) scattering is a highly sensitive and selective vibrational spectroscopic technique with a broad range of applications from polyaromatic hydrocarbons (PAHs) to biomolecular systems (peptides/proteins and nucleic acids) and catalysts. The interpretation of experimental UVRR spectra is not as straightforward as in purely vibrational Raman scattering (Placzek approximation) due to the involvement of higher lying electronic states and vibronic coupling. This necessitates the comparison with theoretical UVRR spectra computed by electronic structure calculations. Anthracene is an ideal model system for such a comparison between experiment and theory because it is rigid, symmetric, and of moderate size. By taking into account Herzberg–Teller contributions including Duschinsky effects, bulk solvent effects, and anharmonic contributions, a good qualitative agreement close to the resonance condition is achieved. The present study shows that within the framework of time‐dependent density functional theory (TD‐DFT), a general and robust approach for the analysis and interpretation of resonance Raman spectra of medium‐ to large‐size molecules is available. [ABSTRACT FROM AUTHOR]

The growing biotechnology industry has focused a lot of attention on biosurfactants because of several advantages over synthetic surfactants. These benefits include worldwide public health, environmental sustainability, and the increasing demand from sectors for environmentally friendly products. Replacement with biosurfactants can reduce upto 8% lifetime CO 2 emissions avoiding about 1.5 million tons of greenhouse gas released into the atmosphere. Therefore, the demand for biosurfactants has risen sharply occupying about 10% (∼10 million tons/year) of the world production of surfactants. Biosurfactants' distinct amphipathic structure, which is made up of both hydrophilic and hydrophobic components, enables these molecules to perform essential functions in emulsification, foam formation, detergency, and oil dispersion—all of which are highly valued characteristic in a variety of sectors. Today, a variety of biosurfactants are manufactured on a commercial scale for use in the food, petroleum, and agricultural industries, as well as the pharmaceutical and cosmetic industries. We provide a thorough analysis of the body of knowledge on microbial biosurfactants that has been gained over time in this research. We also discuss the benefits and obstacles that need to be overcome for the effective development and use of biosurfactants, as well as their present and future industrial uses. [Display omitted] • Biosurfactant are versatile biomolecule being explored by various industries. • Glycolipids are among the most effective biosurfactants for industrial applications. • Role of biosurfactants in biomedical applications and PAH degradation. • Renewable substrates can be used for large-scale biosurfactant production. [ABSTRACT FROM AUTHOR]

The Pd0/AuI mediated [C1+C2] cross‐coupling reactions of [W(≡CBr)(CO)2(Tp*)] (Tp*=hydrotris(dimethylpyrazolyl)borate) and trimethylsilylethynyl‐substituted arenes afford new polycyclic aromatic hydrocarbon propargylidynes [W(≡CC≡CR)(CO)2(Tp*)] (R=9‐anthracenyl, 1‐pyrenyl). The strategy extends to the first bis(propargylidyne) and bis(pentadiynylidyne) complexes bridged by phenyl or anthracenyl spacers, and to a tetrakis(propargylidyne) connected through a pyrene core. [ABSTRACT FROM AUTHOR]

• Significant molecular effects of chemically dispersed oil without phenotypic changes in larval mahi. • Corexit 9500A exposure does not induce significant changes in expression. • Alterations in visual and calcium pathways prior to observable cardiotoxicity. • Crude oil toxicity was not impacted by Corexit concentration. Crude oil and polycyclic aromatic hydrocarbon (PAH) exposure in early life stage fish has been well-characterized to induce phenotypic malformations such as altered heart development and other morphological impacts. The effects of chemical oil dispersants on toxicity are more controversial. To better understand how chemical dispersion of oil can impact toxicity in pelagic fish, embryos of mahi-mahi (Coryphaena hippurus) were exposed to three concentrations of the chemical dispersant Corexit 9500A, or Corexit 9500A-oil mixtures (chemically enhanced water accommodated fractions: CEWAF) of Deepwater Horizon crude oil for 48 h. RNA sequencing, gene ontology enrichment, and phenotypic measurements were conducted to assess toxicity. Exposure to Corexit 9500A altered expression of less than 50 genes at all concentrations (2.5, 5, and 10 mg/L nominal concentration) and did not induce acute mortality or phenotypic malformations, corroborating other studies showing minimal effects of Corexit 9500A on developing mahi-mahi embryos. CEWAF preparations contained environmentally relevant ∑PAH concentrations ranging from 1.4 to 3.1 μg/L and similarly did not alter larval morphology. Differentially expressed genes and significantly altered pathways related to cardiotoxicity, visual impairments, and Ca2+ homeostasis reinforced previous work that expression of genes associated with the heart and eye are highly sensitive molecular endpoints in oil-exposed early life stage fish. Differential expression and gene ontology pathways were similar across the three CEWAF treatments, indicating that increased chemical dispersion did not alter molecular outcomes within the range tested here. In addition, significant sublethal molecular responses occurred in the absence of observable phenotypic changes to the heart, indicating that effects of oil on early life stage fish may not be completely dependent on cardiac function. [ABSTRACT FROM AUTHOR]

Polyaromatic hydrocarbon, rhizoremediation, biostimulation and bioaugmentation, hydrocarbon contaminants, bioremediaiton Bioaugmentation of indigenous fungi resulted in an important shift of the bacterial populations, which was also linked to HMW-PAHs biodegradation efficiency, compared to biostimulation. Keywords: polyaromatic hydrocarbon; bioremediaiton; rhizoremediation; biostimulation and bioaugmentation; hydrocarbon contaminants EN polyaromatic hydrocarbon bioremediaiton rhizoremediation biostimulation and bioaugmentation hydrocarbon contaminants 1 3 3 07/24/21 20210722 NES 210722 Polyaromatic hydrocarbons (PAHs) are hazardous organic molecules with mutagenic, carcinogenic and genotoxic effects. [Extracted from the article]

Polycyclic aromatic hydrocarbons (PAHs) that increasingly emanating from natural and human activity sources are invisible pollutants and the presence of even minute amounts of these substances makes them undesirable due to their negative attributes. The PAHs extraction and removal from effluents are major steps for analysis and removal. Chemical, biological and physical approaches are used for the removal of PAHs from wastewater. However, some of these techniques have toxic by-products. Currently, physical approaches such as liquid-liquid solvent extraction, filtration, and adsorption appear to be the best methods due to their safety, affordability, universal nature and ease of operation. However, some of the materials used in the currently available physical methods face the challenges of fouling, low recovery, their relatively long extraction time and high usage of toxic solvent. To overcome these limitations, and for the cleaner production of water, the incorporation of carbon nanotubes (CNTs) into existing physical procedures without distorting their existing structural architectures is proposed. CNTs are considered because hydrophobic hollow pores of CNTs absorb most aromatic pollutants while allowing the friction-free passage of water without consuming much energy. The functionalization of CNTs with various receptors and groups further permit the selective trapping of pollutants of interest. The ability of the proposed methods to cheaply and sustainably remove PAHs from contaminated water will make hitherto carcinogenic polluted water cleaner for public consumption. This comprehensive article presents an extensive literature review of CNTs and their use for various physical techniques. It further presents CNT as a central focus, with an in-depth critical analysis of the state-of-the-art trends of PAH removal using CNTs, current hurdles and future challenges, so that it could be used as a reference manual adding scientific value for developing any future methods for water purification and the removal of any aromatic pollutants. [ABSTRACT FROM AUTHOR]

Surface sediments from a 160-km stretch of the River Clyde, Scotland, were analysed for persistent organic pollutants to investigate distribution, source and environmental effect. Glasgow's urban tributaries polyaromatic hydrocarbons (PAH) ranged from 2.3 to 4226mgkg–1, total petroleum hydrocarbons (TPH) 72 to 37879mgkg–1 and polychlorinated biphenyls (PCB) 3 to 809μgkg–1, which were more polluted than the upper River Clyde PAH that ranged from 0.1 to 42mgkg–1, TPH 3 to 260mgkg–1 and PCB 2 to 147μgkg–1. Intermediate values of the inner Clyde estuary PAH ranging from 0.6 to 30mgkg–1, and PCB ranging from 5 to 130μgkg–1, were attributed to point sources and sediment transfer from the urban tributaries. Comparison with sediment quality criteria suggested possible adverse effects on aquatic biota. PAH isomeric ratios confirmed a pyrolytic source throughout the Clyde and benzo[ a ]pyrene/benzo[ g,h,i ]perylene ratios >0.6 confirmed that upper, urban and estuarine domains all to a lesser or greater extent accumulated PAH from traffic emissions. The degree of chlorination determined from PCB homologues differed in each of the three domains, suggesting variable source or that the process aerobic/anaerobic degradation varied in each of the three domains. The anthropogenic impact of the city of Glasgow can be quantified in that the urban tributary sediment mean values were 60 (PAH), 33 (TPH) and 11 (PCB) times higher than the rural upper Clyde counterpart. [ABSTRACT FROM AUTHOR]

Abstract In this review, we summarize recent progress in experimental approaches to the investigation of the unoccupied electronic structures of organic ultrathin films, based on a combination of spectroscopic and microscopic techniques. At the molecule/substrate interface, electronic structures are greatly affected by the geometrical structures of adsorbed molecules. In addition, a delicate balance between substrate-molecule and intermolecular interactions plays an important role in the formation of complex polymorphism. In this context, we have clarified the correlation between geometric and electronic structures using a combination of two-photon photoemission (2PPE) spectroscopy, low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). Organic ultrathin films of metal phthalocyanines and polycyclic aromatic hydrocarbons (naphthalene, rubrene and perylene) on graphite substrates were examined as model systems. Depending on the substrate temperature and coverage, unique morphologies, including well-ordered films, a metastable phase and a two-dimensional gas-like phase, were determined at the molecular level. The data show that variations in molecular orientation have a significant impact on the occupied/unoccupied electronic structures. In addition to static information regarding electronic states, ultrafast electron excitation and relaxation dynamics can be tracked in real time on the femtosecond scale by time-resolved 2PPE spectroscopy. The excited electron dynamics of rubrene films are discussed herein, taking into account structural information, in the presence and absence of an overlap of the wave function with the substrate. Spatial resolution at the molecular level is also obtainable via STM-based local spectroscopy and mapping, which have been utilized to elucidate the spatial extent of unoccupied orbitals in real space. Visible photon emissions from the unoccupied states of perylene monolayer films were observed using 2PPE, representing a characteristic deexcitation process from electronically excited states, depending on the surface structure. These spectroscopic and molecular level microscopic investigations provide fundamental insights into the electronic properties of organic/substrate interfaces. [ABSTRACT FROM AUTHOR]

The detection of fluorescence with submolecular resolution enables the exploration of spatially varying photon yields and vibronic properties at the single-molecule level. By placing individual polycyclic aromatic hydrocarbon molecules into the plasmon cavity formed by the tip of a scanning tunneling microscope and a NaCl-covered Ag(111) surface, molecular light emission spectra are obtained that unravel vibrational progression. In addition, light spectra unveil a signature of the molecule even when the tunneling current is injected well separated from the molecular emitter. This signature exhibits a distance-dependent Fano profile that reflects the subtle interplay between inelastic tunneling electrons, the molecular exciton and localized plasmons in at-distance as well as on-molecule fluorescence. The presented findings open the path to luminescence of a different class of molecules than investigated before and contribute to the understanding of single-molecule luminescence at surfaces in a unified picture. [ABSTRACT FROM AUTHOR]