Aromatic Hydrocarbons Research Articles

Aryl hydrocarbon receptor dynamics in esophageal squamous cell carcinoma: From immune modulation to therapeutic opportunities

Esophageal squamous cell carcinoma (ESCC) is a substantial global health burden. Immune escape mechanisms are important in ESCC progression, enabling cancer cells to escape the surveillance of the host immune system. One key player in this process is the Aryl Hydrocarbon Receptor (AhR), which influences multiple cellular processes, including proliferation, differentiation, metabolism, and immune regulation. Dysregulated AhR signaling participates in ESCC development by stimulating carcinogenesis, epithelial-mesenchymal transition, and immune escape. Targeting AhR signaling is a potential therapeutic approach for ESCC, with AhR ligands showing efficacy in preclinical studies. Additionally, modification of AhR ligands and combination therapies present new opportunities for therapeutic intervention. This review aims to address the knowledge gap related to the role of AhR signaling in ESCC pathogenesis and immune escape.

Ecological and Geochemical Assessment of the State of Soils in the City of Baikalsk According to the Content of Polycyclic Aromatic Hydrocarbons

The pollution of the topsoils of the city of Baikalsk (Irkutsk region) under the influence of industrial emissions and wastes of the Baikal Pulp and Paper Mill (BPPM) was studied. The content of 16 individual PAH structures in samples of urban and background soils taken during the soil geochemical survey in the summer of 2019 was analyzed. Relatively low levels of PAH content were found in the lignin sludge from the BPPM and СHP ash. The concentration of total PAHs in CHP ash reaches 46 mg/ kg with a predominance of low molecular weight compounds (the proportion of naphthalene and its homologues is 24% and 34% of the total PAHs, respectively), among high molecular weight PAHs, 5-nuclear benzo(b)fluoranthene dominates (16%). In lignin sludge, the amount of PAHs is 7.16 mg/kg with the predominance of benzo(b)fluoranthene (83%). In the soils of Baikalsk, the average total content of PAHs (38.4 mg/kg) is 5 times higher than the background content. In urban soils, 4–5-nuclear fluoranthene (61.1%) and benzo(b)fluoranthene (29.4%) prevail. This makes it possible to attribute soil pollution to the fluoranthene type. The soils of the motor transport (total PAH 105 mg/kg) and industrial (59.5 mg/ kg) zones are the most polluted, where the most contrasting PAH anomalies were formed. In descending order of the amount of PAHs, the land use zones of the city form a series: motor transport industrial residential one-storey railway transport residential multi-storey recreational zone. Several local anomalies in the amount of PAHs are distinguished, forming two large pollution halos in the western and eastern parts of the city. The leading factors in the accumulation of high molecular weight PAHs in soils are acid-alkaline conditions and soil organic matter, while the accumulation of low molecular weight polyarenes is mainly controlled by pH. The environmental hazard of pollution of Baikalsk soils with polyarenes is due to benzo(b)fluoranthene, its contribution is 83.5%.

Chronic and Periodic Effects of Smoke from Crop Residue Combustion on Soil Enzymatic Activity

Wildfires lead to the emission of large volumes of toxic smoke, which is transported hundreds of kilometres away from the fires and can have a negative impact on soil, biota and humans. A series of modelling experiments on pyrogenic fumigation of soil were carried out to assess the effects of gaseous products from wildfires on soil biochemical parameters. The effects of chronic exposure to gaseous substances and periodic, repetitive effects of smoke exposure on soil were determined. The results were compared with a single intensive smoke exposure. It was found that pyrogenic impact significantly affected the change of enzymatic activity of ordinary chernozem. The degree of influence depended on the duration and periodicity of smoke exposure. In all experiments enzymes of oxidoreductase class (catalase, peroxidase, polyphenol oxidase) were more sensitive to fumigation than invertase from hydrolase class. The reason of suppression of enzymatic activity of soils is high concentrations of toxic gases. The following concentrations exceeded the maximum permissible concentrations for atmospheric air: CO 714 times, phenol (hydroxybenzene) 441 times, acetaldehyde 24100 times, formaldehyde 190 times. Accumulation of polycyclic aromatic hydrocarbons (PAHs) in soil after fumigation was revealed, the total content of PAHs was 377 ng/g. The highest values were recorded for naphthalene, where the concentration was 4.4 times higher than the maximum permissible and phenanthrene 2.8 times higher than the maximum permissible. It was found that 60-minute intensive smoke affects the soil to a lesser extent than chronic and periodic. Indicators of enzymatic activity of chernozem after such fumigation decreased by 15-33% depending on the enzyme, in chronic and periodic by 41-84 and 31-78%, respectively. The obtained data indicate a significant effect of smoke on enzymatic activity of soils under chronic and periodic exposure to gaseous products of combustion.

Metagenomic survey reveals hydrocarbon biodegradation potential of Canadian high Arctic beaches

BackgroundDecreasing sea ice coverage across the Arctic Ocean due to climate change is expected to increase shipping activity through previously inaccessible shipping routes, including the Northwest Passage (NWP). Changing weather conditions typically encountered in the Arctic will still pose a risk for ships which could lead to an accident and the uncontrolled release of hydrocarbons onto NWP shorelines. We performed a metagenomic survey to characterize the microbial communities of various NWP shorelines and to determine whether there is a metabolic potential for hydrocarbon degradation in these microbiomes.ResultsWe observed taxonomic and functional gene evidence supporting the potential of NWP beach microbes to degrade various types of hydrocarbons. The metagenomic and metagenome-assembled genome (MAG) taxonomy showed that known hydrocarbon-degrading taxa are present in these beaches. Additionally, we detected the presence of biomarker genes of aerobic and anaerobic degradation pathways of alkane and aromatic hydrocarbons along with complete degradation pathways for aerobic alkane degradation. Alkane degradation genes were present in all samples and were also more abundant (33.8 ± 34.5 hits per million genes, HPM) than their aromatic hydrocarbon counterparts (11.7 ± 12.3 HPM). Due to the ubiquity of MAGs from the genus Rhodococcus (23.8% of the MAGs), we compared our MAGs with Rhodococcus genomes from NWP isolates obtained using hydrocarbons as the carbon source to corroborate our results and to develop a pangenome of Arctic Rhodococcus. Our analysis revealed that the biodegradation of alkanes is part of the core pangenome of this genus. We also detected nitrogen and sulfur pathways as additional energy sources and electron donors as well as carbon pathways providing alternative carbon sources. These pathways occur in the absence of hydrocarbons allowing microbes to survive in these nutrient-poor beaches.ConclusionsOur metagenomic analyses detected the genetic potential for hydrocarbon biodegradation in these NWP shoreline microbiomes. Alkane metabolism was the most prevalent type of hydrocarbon degradation observed in these tidal beach ecosystems. Our results indicate that bioremediation could be used as a cleanup strategy, but the addition of adequate amounts of N and P fertilizers, should be considered to help bacteria overcome the oligotrophic nature of NWP shorelines.

Stepwise One-Shot Borylation Reactions for Intersecting DABNA Substructures Exhibiting Bright Yellow‒Green Electroluminescence with EQE Beyond 40% and Mild Roll-Off.

Boron/nitrogen (B/N)-doped polycyclic aromatic hydrocarbons (PAHs) with the multiple resonance (MR) effect are promising for organic light-emitting diodes (OLEDs) because of their narrowband emission and thermally activated delayed fluorescence (TADF) characteristics. Nevertheless, exploring the variety of such emitters is challenging because of the tricky and limited synthetic protocols. Herein, we designed a novel B/N-doped PAH, L-DABNA-1, whose backbone (L-DABNA) could not be achieved via conventional routes (e.g., one-pot borylation or one-shot borylation). We successfully synthesized it through stepwise one-shot borylations with precisely introducing decorations. The unique MR backbone with intersecting DABNA substructures sharing an aniline group, avoiding any para-N-π-B motif, allows L-DABNA-1 to maintain narrowband TADF emission while significantly redshifting to the yellow-green region with a reverse intersystem crossing rate (kRISC) of 1.28 × 105 s-1. An L-DABNA-1-based OLED device achieved a maximum external quantum efficiency (EQE) of over 40% and maintained a high EQE of 36.3% at 1000 cd m-2, with a current efficiency reaching ~170 cd A-1. This work not only demonstrated the great potential of stepwise borylations in synthesizing B/N-doped PAH backbones, expanding their chemical space, but also provided a promising pathway for exploring MR-TADF emitters at longer wavelengths.

Effect and interaction of PINK1 genetic polymorphisms and environmental factors on blood pressure in COEs-exposed workers.

Coke oven emissions (COEs) contain a variety of polycyclic aromatic hydrocarbons (PAHs), which can cause damage to the human cardiovascular system. In addition, myocardial mitochondria are susceptible to damage in hypertensive patients. However, it is not clear whether genetic variation, in single nucleotide polymorphisms (SNPs) in PINK1 affects COEs exposure-induced abnormal blood pressure. We surveyed and tested 518 workers exposed to COEs and statistically analyzed them with SPSS 21.0 software. SBP was greater in the high-exposure group than in the low-exposure group. Generalized linear model analysis showed that the interaction of PINK1 rs3738136 (GA+AA) and COEs had an effect on SBP [β(95%CI) = -6.537(-12.072, -1.002), p = 0.021] and DBP [β(95%CI) = -4.811(-8.567, -1.056), p = 0.012]. This study is the first to identify the role of PINK1 rs3738136 in COE- induced abnormal blood pressure, and to prove that the abnormal blood pressure of workers is the result of environmental and genetic factors.

SOURCE APPORTIONMENT OF ATMOSPHERIC AND SEDIMENTARY PAHS FROM KOLKATA, INDIA USING COMPOUND-CLASS-SPECIFIC RADIOCARBON ANALYSIS (CCSRA)

ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are major air pollutants that are ubiquitously produced by the combustion of organic materials, and it is extremely important to identify their pollution sources. In this study, molecular fingerprinting and compound class-specific radiocarbon dating (CCSRA) were performed on PAHs from canal sediments and air samples collected in Kolkata, India’s third largest city (population approximately 16 million), where PAHs pollution has been a serious problem. Average PAH (Σ12-parent PAHs) concentrations in air samples were 65.1 ng m–3 in summer and 70.9 ng m–3 in winter and in canal sediments were 32.7 µg g–1, which are classified as “very high-level” pollution. Molecular fingerprinting using methyl-PAH/PAH (MPAHs/PAHs) ratios and isomer pair ratios with molecular weights of 178, 202, 228, and 276 suggested that wood and coal combustion were the dominant sources of PAHs in the sediment, and that atmospheric PAHs were influenced by oil combustion in addition to them. The fraction of contemporary carbon (ƒC) of sedimentary PAHs (0.056–0.100), together with the extremely low MPAHs/PAHs ratio results, lead to the conclusion that the major source of the high concentration of PAHs in the canals is from coal combustion. On the other hand, the ƒC of atmospheric PAHs (0.272–0.369) was close to the share of biomass fuels in India’s domestic fuel consumption in 2011 (about 35%). Furthermore, the observed ƒC-discrepancy between atmospheric and sedimentary PAHs in the same urban environment was interpreted to give an insight into the loading pathway of PAHs to canal sediments in Kolkata.

Production of Bio-Oil from Sugarcane Bagasse through Hydrothermal Liquefaction Processes with Modified Zeolite Socony Mobil-5 Catalyst

In response to the increasing global demand for sustainable energy alternatives, this research explores the efficient conversion of sugarcane bagasse to bio-oil through hydrothermal liquefaction (HTL) processes with modified Zeolite Socony Mobil-5 catalysts (ZSM-5). The study systematically investigates the impact of feedstock quantity, reaction temperature, duration, and catalyst loading on bio-oil yield and quality. Optimisation experiments revealed that a feedstock amount of 10 grammes, an HTL temperature of 340 °C for 60 min and a ZSM-5 catalyst loading of 3 grammes resulted in the highest bio-oil yield. Furthermore, the introduction of Ni and Fe metals to ZSM-5 exhibited enhanced catalytic activity without compromising the structure of the zeolites. Comprehensive characterisation of modified catalysts using SEM-EDS, XRD, TGA, TEM, and FTIR provided insight into their structural and chemical properties. The successful incorporation of Ni and Fe into ZSM-5 was confirmed, highlighting promising applications in hydrothermal liquefaction. Gas chromatography–mass spectrometry (GC-MS) analysis of bio-oils demonstrated the effectiveness of the 2% Fe/ZSM-5 catalyst, highlighting a significant increase in hydrocarbon content. FTIR analysis of the produced bio-oils indicated a reduction in functional groups and intensified aromatic peaks, suggesting a shift in chemical composition favouring aromatic hydrocarbons. This study provides valuable information on HTL optimisation, catalyst modification, and bio-oil characterisation, advancing the understanding of sustainable biofuel production. The findings underscore the catalytic prowess of modified ZSM-5, particularly with iron incorporation, in promoting the formation of valuable hydrocarbons during hydrothermal liquefaction.

Assessment of Cytotoxicity and Genotoxicity Induced by Diesel Exhaust Particles (DEPs) on Cell Line A549 and the Potential Role of Amide-Functionalized Carbon Nanotubes as Fuel Additive

Epidemiological studies have consistently linked air pollution to severe health risks. One strategy to reduce the impact of combustion products from engines is adding additives to the fuel. Potential benefits have been observed in terms of performance and emissions, as well as in decreasing fuel consumption. However, the associated emission of particulate matter into the environment may have unforeseen health effects. This study examines the effects of diesel exhaust particles (DEPs) from diesel fuel mixed with amide-functionalized carbon nanotubes (CNTF). The aim is to analyze the properties of DEPs and determine their toxic effects on lung cells. The DEPs were characterized using scanning and transmission electron microscopy, while the polycyclic aromatic hydrocarbons (PAHs) were analyzed through gas chromatography. Various assays were conducted to assess cell viability, apoptosis, oxidative stress, and DNA damage. The addition of CNTF to diesel fuel altered the morphology and size of the particles, as well as the quantity and composition of PAHs. At the cellular level, diesel DEPs induce higher levels of reactive oxygen species (ROS) production, DNA damage, apoptosis, and cytotoxicity compared to both CNTF and diesel–CNTF DEPs. These findings suggest that the nano-additives enhance energy efficiency by reducing pollutants without significantly increasing cell toxicity.

Occupational Exposure of On-Shift Ottawa Firefighters to Flame Retardants and Polycyclic Aromatic Hydrocarbons

Firefighters can be exposed to complex mixtures of airborne substances, including hazardous substances released during structural fires. This study employed silicone wristbands (SWBs) as passive samplers to investigate potential exposure to polycyclic aromatic hydrocarbons (PAHs) and flame retardants (FRs). SWBs were deployed at different areas of four fire stations, in four truck cabins, and at an office control location; they were also donned outside the jackets of 18 firefighters who responded to fire calls. Overall, office areas had significantly lower PAHs than fire station areas. Vehicle bays and truck cabins had significantly higher concentrations of low molecular weight (LMW) PAHs than sleeping and living room areas. For organophosphate ester flame retardants (OPFRs), tri-n-butyl phosphate (TnBP) and tris(1-chloro-2-propyl) phosphate (TCPP) were detected in all the samples; 2-ethylhexyl diphenyl phosphate (EHDPP) was more frequently detected in the fire station areas. Triphenyl phosphate (TPP) concentrations were highest in the truck cabin and office areas, and tris(1,3-dichloro-2-propyl)phosphate (TDCPP) was highest in truck cabins. Thirteen of 16 PAHs and nine of 36 OPFRs were detected in all the SWBs worn by firefighters, and tris (2-butoxyethyl) phosphate (TBEP) was the predominant OPFR. Levels of LMW PAHs were significantly lower when firefighters did not enter the fire. LMW PAHs, HMW (high molecular weight) PAHs, and EHDPP were significantly elevated when heavy smoke was reported. This work highlights the potential for occupational exposure to PAHs and flame retardants in some fire station areas; moreover, factors that may influence exposure during fire suppression. Whilst firefighters’ occupational exposure to PAHs is likely related to fire suppression and exposure to contaminated gear and trucks, exposure to OPFRs may be more related to their presence in truck interiors and electronics.

Polycyclic Aromatic Hydrocarbon Contamination in Yogurt: Levels, Compositions, and Risks

Polycyclic Aromatic Hydrocarbon Contamination in Yogurt: Levels, Compositions, and Risks

Microcrystalline Engineering of Anthracite-Based Carbon Via Salt-Assisted Ball Milling for Enhanced Sodium Storage Performance.

Coal-based carbon material, characterized by abundant resources and low cost, has gained considerable interests as a promising anode candidate for sodium-ion batteries (SIBs). However, the coal-based carbon generally shows inferior Na-storage performance due to its highly-ordered microstructure with narrow interlayer spacing. Herein, a salt-assisted mechanical ball-milling strategy is proposed to disrupt the polycyclic aromatic hydrocarbon structure in anthracite molecules, thereby reducing the microcrystalline regularity of the derived carbon during following pyrolysis process. In addition, the induced C─O─C bonds during ball-milling process can alter the pyrolysis behavior of anthracite and restrain the formation of surface defects. Consequently, in contrast to pristine anthracite-based pyrolytic carbon, which exhibits a Na-storage capacity of 198.4 mAh g-1 with a low initial Coulombic efficiency (ICE) of 65.1%, the ball-milling modified carbon assisted by NaCl salt (NAC), with enhanced structural disordering and reduced surface defects, demonstrate significantly improved Na-storage capacity of 332.1 mAh g-1 and ICE value of 82.0%. The NAC electrode also realizes excellent cycle and rate performance, retaining a capacity of 196.0 mAh g-1 at 1 C after 1000 cycles. Furthermore, when coupled with NaNi1/3Fe1/3Mn1/3O2 cathode, the assembled Na-ion full cell deliveres an exceptional electrochemical performance, highlighting its promising prospect as high-performance anode for SIBs.

Polymorphism of pyrene on compression to 35 GPa in a diamond anvil cell

Structural studies of pyrene have been limited to below 2 GPa. Here, we report on investigations of pyrene up to ~35 GPa using in situ single-crystal synchrotron X-ray diffraction in diamond anvil cells and ab initio calculations. They reveal the phase transitions from pyrene-I to pyrene-II (0.7 GPa), and to the previously unreported pyrene-IV (2.7 GPa), and pyrene-V (7.3 GPa). The structure and bonding analysis shows that gradual compression results in continuous compaction of molecular packing, eventually leading to curvature of molecules, which has never been observed before. Large organic molecules exhibit unexpectedly high conformational flexibility preserving pyrene-V up to 35 GPa. Ab initio calculations suggest that the phases we found are thermodynamically metastable compared to pyrene-III previously reported at 0.3 and 0.5 GPa. Our study contributes to the fundamental understanding of the polymorphism of polycyclic aromatic hydrocarbons and calls for further theoretical exploration of their structure–property relationships.

Integrated evaluation of workplace exposures and biomarkers of bladder cancer among textile dyeing workers

BackgroundThe textile industry is the second risk factor for bladder cancer, after smoking. Previous studies focused on the impact of exposure to high concentrations of bladder carcinogenic chemicals in the textile dyeing industry on the elevation of bladder cancer biomarkers. This study aimed to evaluate bladder carcinogenic air pollutants in a textile dyeing factory and investigate its role and the role of serum 25-hydroxyvitamin D (25-OH vit. D) on cancer bladder biomarkers in exposed workers.MethodsA cross-sectional study was conducted. Particulate and vapor forms of polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) were monitored in the printing, dyeing, and preparing sections of a textile factory. Bladder tumor antigen (BTA), nuclear matrix protein 22 (NMP-22), and 25-OH vit. D were estimated in all the exposed workers (147 exposed workers) and in workers not occupationally exposed to chemicals (130 unexposed workers).ResultsAromatic bladder carcinogenic compounds were either in low concentrations or not detected in the air samples of working areas. BTA and NMP-22 of exposed workers were not significantly different from the unexposed. However, 25-OH vit. D was significantly lower in the exposed than unexposed workers. There was a significant inverse correlation between 25-OH vit. D and duration of exposure in exposed workers.ConclusionThe mean levels of PAHs and VOCs were within the safe standard levels in the working areas. The non-significant difference in BTA and NMP-22 between the exposed and unexposed groups suggests the presence of occupational exposures to safe levels of bladder carcinogenic aromatics, while the significantly lower 25-OH vit. D levels among the exposed than the unexposed groups could suggest the potential association of 25-OH vit. D with occupational exposures to low levels of PAHs and VOCs, and this association was found to be inversely correlated with the duration of exposures. Accordingly, more specific predictor tests must be applied for early diagnosis of bladder cancer among the exposed workers.

Geniposidic Acid Attenuates Chronic Tubulointerstitial Nephropathy Through Regulation of the NF-ƙB/Nrf2 Pathway Via Aryl Hydrocarbon Receptor Signaling.

Renal fibrosis is an outcome of chronic kidney disease, independent of the underlying etiology. Renal fibrosis is caused primarily by oxidative stress and inflammation. We identified the components of Plantaginis semen and elucidated their anti-fibrotic and anti-inflammatory mechanisms. The renoprotective components and underlying molecular mechanisms of P. semen were investigated in rats with adenine-induced chronic tubulointerstitial nephropathy (TIN) and in idole-3-acetic acid (IAA)-stimulated NRK-52E cells. Acetate and n-butanol extracts were found to be the bioactive fractions of P. semen. A total of 65 compounds including geniposidic acid (GPA), apigenin (APG), and acteoside (ATS) were isolated and identified. Among the seven main extract components, treatment with GPA, APG, and ATS reduced the serum levels of creatinine and urea in TIN rats. Mechanistically, GPA ameliorated renal fibrosis through repressing aryl hydrocarbon receptor (AHR) signaling and regulating redox signaling including inhibiting proinflammatory nuclear factor kappa B (NF-ƙB) and its target gene products as well as activated antioxidative nuclear factor-erythroid-2-related factor 2 (Nrf2) and its downstream target gene products in both TIN rats and IAA-stimulated NRK-52E cells. The inhibitory effect of GPA on AHR, NF-Ƙb, and Nrf2 signaling were partially abolished in IAA-stimulated NRK-52E cells treated with CH223191 compared with untreated IAA-stimulated NRK-52E cells. These data demonstrated that GPA alleviates oxidative stress and inflammation partly by suppressing AHR signaling.

Metal-free alkyne annulation enabling π-extension of boron-doped polycyclic aromatic hydrocarbons.

A C-H functionalizing annulation reaction of boron-doped polycyclic aromatic hydrocarbons (PAHs) with alkynes is described. This metal-free π-extension provides a new synthetic route to fusion atom B-doped polycyclic aromatic hydrocarbons (PAHs) that is demonstrated with the synthesis of a family of new, functionalized, structurally constrained 6a,15a-diborabenzo[tuv]naphtho[2,1-b]picenes. These annulation products exhibit deep LUMO energy levels, strong visible-range absorptions, and sterically accessible π-systems that can adopt herringbone or π-stacked solid-state structures based on choice of substituents. From regioselectivity and DFT calculations, we propose an annulation mechanism involving intramolecular electrophilic aromatic substitution of a zwitterionic intermediate.

Beekeeping breakthrough: unveiling hive health with a portable membrane inlet mass spectrometry detection method.

Supporting bee populations is essential considering threats posed by human activities like pesticide usage and habitat destruction. However, the current methods for monitoring and analyzing beehives and their surrounding environments are invasive, complex, and time-consuming. These methods often rely heavily on laboratory analyses, making them difficult to implement independently in the field. This study explores the application of portable membrane inlet mass spectrometer (MIMS) for noninvasive hive analysis, demonstrating its ability to detect various compounds indicative of hive conditions and environmental stressors. In addition to the expected compounds found in beehives, such as α-bergamotene, hexadecanoic acid, heptadecane, hexadecanamide, α-bisabolol-, 9-octadecenamide, (Z) - , and benzaldehyde, unexpected compounds, pollutants, like indane (polycyclic aromatic hydrocarbon) and carbofuran (pesticide), were also detected. The MIMS detection method provides rapid, accurate, and real-time results, making it suitable for preventive measures against bee diseases and integral to environmental biomonitoring. This integration of technology represents a significant advancement in bee conservation efforts, offering hope for the future of both bees and ecosystems.

Inverse Vulcanization of Vinyl-polycyclic Aromatic Hydrocarbon Monomers and Dynamic Covalent Polymerization with Liquid Crystalline Monomers

Inverse Vulcanization of Vinyl-polycyclic Aromatic Hydrocarbon Monomers and Dynamic Covalent Polymerization with Liquid Crystalline Monomers

Synthesis, Stable Radical Anion and Energy Storage Performance of Pentacene Tetraimides.

Imide functionalization has been widely proved to be an effective approach to enrich optoelectronic properties of polycyclic aromatic hydrocarbons (PAHs). However, appending multiple imide groups onto linear acenes is still a synthetic challenge. Herein, we demonstrate that by taking advantage of a "breaking and mending" strategy, a linear pentacene tetraimides (PeTI) was synthesized through a three-step sequence started from the naphthalene diimides (NDI). Compared with the parent pentacene, PeTI shows a deeper-lying lowest unoccupied molecular orbital (LUMO) energy level, narrower bandgap and better stability. The redox behavior of PeTI was firstly evaluated by generating a stable radical anion specie with the assistance of cobaltocene (CoCp2), and the structure of the electron transfer (ET) complex was confirmed by the X-ray crystallography. Moreover, due to the presence of multiple redox-active sites, we are able to show that the state-of-the-art energy storage performance of the dealkylated PeTI (designated as PeTCTI) in organic potassium ion batteries (OPIBs) as an anode. Our results shed light on the application of multiple imides functionalized linear acenes, and the reported synthetic strategy provides an effective way to get access to longer nanoribbon imides with fascinating electronic properties.

Assessment of Hydrocarbon Contamination Using 2D Resistivity Imagining Method and Geochemical Analysis in Ibadan, Southwestern Nigeria

The study examined the use of 2D resistivity imaging survey and geochemical analysis to map and assess the level of soil contamination due to hydrocarbon spillage in Araromi Auto Spare Parts Market Ibadan, Southwestern Nigeria. The objectives are to provide 2D inverted resistivity sections beneath the study area, delineate anomalously low resistivity zones indicative of long-term hydrocarbon contamination in the sections, and determine concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in the suspected soils. Five traverses were run using Wenner array with electrode spacing varied from 5 m to 15 m and station increment of 5 m. The resistivity data were processed by using 2D inversion procedure to generate the 2D inverted resistivity sections. Geochemical analysis was conducted on five soil samples collected at 1 m depth in the low resistivity zones delineated on the 2D inversion sections, to determine the concentration of Polycyclic Aromatic Hydrocarbons (PAHs) to assess the level of contamination. The 2D inverted sections delineated low resistivity anomalies, ranging from 1.25 Ωm to 5.54 Ωm, characteristic of mature biodegraded hydrocarbon contamination. The results of geochemical analysis revealed total PAH concentration of 1390 µg/kg to 16140 µg/kg suggesting that the study area is heavily contaminated by the used motor oil. The combined use of 2D resistivity imaging and geochemical analysis has shown that soils beneath the study area has been heavily contaminated by the used motor oil, and may constitute potential health risk to the soil and groundwater systems in its vicinity. The results are expected to serve as useful guide in planning remediation programme.