Aromatic Hydrocarbons Research Articles

Spiro-Fused vs 575-Ringed Boron-Doped Polycyclic π-Systems: Selective Synthesis, Reactivity and Properties.

Incorporation of heteroatoms and/or non-hexagonal rings into polycyclic aromatic hydrocarbons (PAHs) can alter their intrinsic structures and physical properties. However, it is challenging to construct PAHs featuring boron/carbon composition and non-hexagonal combination. Herein, we disclose the selective synthesis of spiro-type and pentagon/heptagon-containing boron-doped polycyclic π-systems by the Scholl reaction. Two spiro-fused organoboranes 1 and 2 and one 575-ringed boron-doped nanographene 3 were synthesized. The key point is that the boron-edged π-system enabled unexpected spiro-formation via dearomatization, whereas the boron-centered π-system enabled desired 575-ringed π-extension via cyclodehydrogenation. The thus-obtained molecules exhibit the intriguing but fully distinct reactivity, electronic structures and properties, for instance, while 2 may react with Brønsted acid to display reversible chemochromism and further convert into 1, 3 possesses very broad absorption, short excited-state lifetime and no fluorescence nature. As disclosed, the boron atom together with the spirocycle region or 575-ringed structural motif significantly contribute to their characteristic properties. Thus, this study sheds light on control over the Scholl reaction using organoborane π-systems and will promote the exploration of more sophisticated polycyclic π-systems as organic reactive and optical scaffolds.

Topological characterization of [n]-triangulenes through degree-based molecular descriptors with the prediction to π-electron energy

Abstract Triangulene and its π-extended homologues are a family of polycyclic aromatic hydrocarbons
with a peculiar chemical structure. They are recognized for their intricate structural configurations
and electrical properties, which make them a promising material for potential uses in spintronics.
They are built of benzenoid rings fused in a triangular manner. Topological indices are widely
utilized as graph theoretical measures for evaluating the physicochemical properties of polycyclic
aromatic hydrocarbons by analyzing their molecular structures, makes them hold a significant position
in the domain of mathematical and computational chemistry. In this study, a mathematical
exploration of topological indices of [n]-triangulenes has been done to establish a comprehensive
understanding of their applications and significance. Generalized expressions for topological indices
have been computed, and their predictive power for various physicochemical properties has been
studied using statistical methods. Also, a quantitative structure-property relationship analysis of
[n]-triangulene’s energetic characteristics has been performed. Moreover, a generalized algebraic
expression to predict the π-electron energy of [n]-triangulene structure has been derived.

Hydrogen ejection from hydrocarbons: Characterization and relevance in soot formation and interstellar chemistry

Polycyclic aromatic hydrocarbons (PAHs) play a major role in the chemistry of combustion, pyrolysis, and the interstellar medium. Production (or activation) of radical PAHs and propagation of their resulting reactions require efficient dehydrogenation, but the preferred method of hydrogen loss is not well understood. Unimolecular hydrogen ejection (i.e., direct C─H bond fission) and bimolecular radical abstraction are two main candidate pathways. We performed a computational study to characterize the role of H ejection, particularly as a driver for radical-centric hydrocarbon-growth mechanisms and particle formation. Electronic structure calculations establish that C─H bond strengths span a broad range of energies, which can be weaker than 30 kcal/mol in some C9 and C13 PAH radicals. At T > 1200 K, calculated thermal rates for hydrogen ejection from weak C─H bonds at zigzag sites on PAH radicals are significantly larger than typical H-abstraction rates. These results are highly relevant in the context of chain reactions of radical species and soot inception under fuel-rich combustion conditions. Furthermore, calculated microcanonical rates that include the additional internal energy released by bond formation (e.g., ring closure to yield C9H9) yield significantly higher rates than those associated with full thermalization. These microcanonical considerations are relevant to the astrochemical processes associated with hydrocarbon growth and processing in the low-density interstellar environment.

Distribution of carcinogenic polycyclic aromatic hydrocarbons in urban soil across major cities of Bihar, India: seasonal variation, source apportionment, and health risk assessment.

This study investigates the distribution of sixteen priority polycyclic aromatic hydrocarbons (PAHs), various sources of PAHs, and their probable cancer-causing risks in the soil samples collected from urban cities in Bihar, India. During the winter season, the ∑16 PAH concentration was dominant and ranged from 979.36 to 5149.37 ngg-1 with a mean value of 2684.79 ngg-1, while for the summer season, it ranged from 690.06 to 4539.55 ngg-1 with a mean value of 2194.31 ngg-1. The (4-ring) PAH compounds were the major contributors, accounting for 40% and 37% in the winter and summer seasons, respectively followed by (5- and 6-ring) PAHs at 30% and 32%, and (2- and 3-ring) PAHs at 29% and 30% in the respective seasons. Carcinogenic PAHs constituted ~ 50% of the ∑16 PAHs, with mean values of 1353.97 ngg-1 and 1098.09 ngg-1 for the winter and summer seasons, respectively. Positive matrix factorization (PMF) confirmed the dominance of fossil fuel burning and biomass burning as a primary source in the urban soil of Bihar. Total mean benzo(a)pyrene equivalent (BaPeq) values for the ∑16 PAHs were 312.04 ngg-1 for the winter season and 262.83 ngg-1 for the summer season. These values were higher in current study sites as compared with other studies. However, the concentration range fell within the limit set by the Canadian soil quality standard (700.00 ngg-1) and exceeded the limit of the Dutch target value (32.96 ngg-1). The Incremental Lifetime Cancer Risk (ILCRs) from dermal and ingestion pathways were approximately 104 to 105 times lower than the inhalation pathway, suggesting greater risk. The study revealed higher mean cancer risk values for children (1.16 × 10-5) and adults (1.03 × 10-5) in the winter season, falling within the unacceptable range (10-6 and 10-4) of carcinogenic risk that might lead to human health risk in the study sites.

An endogenous aryl hydrocarbon receptor ligand induces preeclampsia-like phenotypes in rats.

Preeclampsia (PE) is a hypertensive disorder during human pregnancy. Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor. Exogenous and endogenous AhR ligands can induce hypertension in male rats and mice. Herein, using rats as a model, we tested the hypothesis that over-regulation of endogenous AhR ligands during pregnancy impairs vascular functions by disrupting the transcriptome in the placenta, contributing to the development of PE. Pregnant rats were injected daily with an endogenous AhR ligand, 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), from gestational day (GD) 10 to 19. Maternal mean blood pressure was measured on GD16-20. Proteinuria and uteroplacental blood flow were monitored on GD20. Placentas collected on GD20 were used to determine changes in vascular density and transcriptome. Compared with the vehicle control, ITE elevated maternal mean blood pressure by 22% and 16% on GD16 and 17, respectively. ITE increased proteinuria by 50% and decreased uteroplacental blood flow by 26%. ITE reduced the placental vascular density by 18%. RNA sequencing analysis revealed that ITE induced 1316 and 2020 differentially expressed genes (DEGs) in female and male placentas, respectively. These DEGs were enriched in pathways relevant to heart diseases, vascular functions and inflammation. Bioinformatics analysis also predicted that ITE altered immune cell infiltration in placentas depending on fetal sex. These data suggest that over-regulation of endogenous AhR ligands may lead to PE with impaired vascular functions and disrupted fetal sex-specific transcriptomes and immune cell infiltration in placentas. These AhR ligand-induced DEGs and pathways may represent promising therapeutic targets for PE-induced cardiovascular dysfunctions. KEY POINTS: An endogenous AhR ligand (ITE) elevated maternal blood pressure and proteinuria in pregnant rats, and decreased uteroplacental blood flow and fetal and placental growth, all of which are hallmarks of preeclampsia. ITE reduced vascular density and altered immune cell distribution in rat placentas. ITE dysregulated transcriptomes in rat placentas in a fetal sex-specific manner. These ITE-dysregulated genes and pathways are highly relevant to diseases of heart, vascular functions and inflammatory responses.

Recent Advances in the Synthesis and Application of TS‐1 Zeolite for Green Catalytic Oxidation

AbstractTS‐1 has a unique structure, and TS‐1/H2O2 oxidation system for composition shows excellent catalytic performance in the oxidation of a variety of organic matter. The response conditions of the reaction system are mild, and the ultimate oxidation product is water. It is a typical “green catalytic” system and has received widespread attention from researchers. Here, the synthesis progress of TS‐1 to improve the accessibility and activity of active sites by doping mesoporous and microporous structures into traditional TS‐1 zeolite in recent five years are reviewed, including hydrothermal synthesis, dry gel conversion synthesis, solvent‐free synthesis, microwave assisted synthesis, and isomorphous substitution. Meanwhile, the application of TS‐1/H2O2 system in oxidative desulfurization, ketone ammonia oxidation, olefin epoxidation, and hydroxylation of aromatic hydrocarbons reactions are summarized and discussed. What's more, the reaction mechanism based on TS‐1/H2O2 system is proposed on regarding the isolated skeleton Ti site in titanium‐silicon zeolite as the active central site. Finally, the challenges and future development prospects of TS‐1 zeolite in synthesis and catalytic applications are predicted.

A Special Hydrated Iron Oxyhydroxide for Catalyzing Persulfate to Control Chemical Wastewater Containing Fluoranthene, Phenanthrene, and Pyrene

Water pollution caused by fluoranthene (FLN), phenanthrene (PHE), and pyrene (PYR) has become an increasingly serious issue in recent years. Consequently, finding effective methods to remove these pollutants from aquatic environments is of paramount importance. This study investigated the removal rate of FLN, PHE, and PYR from simulated wastewater using persulfate (PS) and explored the effects of PS catalyzed by three different forms of schwertmannite (sch): sch-1, sch-2, and sch@BC (schwertmannite-biochar composite), and the BET of sch-1, sch-2, sch@BC has been detected, which were 1.09 cm3/g, 11.30 cm3/g, and 6.10 cm3/g. The results showed varying removal rates after a 1 h reaction time for different treatments: For FLN: sch-1+PS (98.5%), sch-2+PS (54.2%), sch@BC+PS (21.1%), and PS alone (14.8%). For PHE: sch-1+PS (94.3%), sch-2+PS (44.1%), sch@BC+PS (28.4%), and PS alone (7.6%). For PYR: sch-1+PS (97.2%), sch-2+PS (52.5%), sch@BC+PS (14.2%), and PS alone (1.7%). Among the catalysts tested, sch-2 (added 0.36 mL H2O2 five times) demonstrated excellent catalytic ability in enhancing the PS removal of FLN, PHE, and PYR. This research provides theoretical support for treating polycyclic aromatic hydrocarbon (PAH)-containing wastewater via persulfate oxidation catalyzed by schwertmannite.

Some Aspects of the Use of Carbon Dioxide as a Carrier and Makeup Gas in GC–FID Analysis

The paper presents the possibility of using carbon dioxide as a carrier gas in capillary gas chromatography (with a stationary liquid phase) to analyze semi-volatile compounds (boiling points of up to 400 °C). Based on the experiments carried out for compounds from the group of organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), the maximum volumetric flow rate (2.4 mL/min for CO2) was determined, enabling the correct separation of the tested standard mixtures (except for two compounds from the OCP group: 4,4′-DDD and Endrin aldehyde and two other pairs of compounds with Rs slightly less than 1.5). Compared to using helium as a carrier gas (and makeup), carbon dioxide produces wider (about 1.6 times) and lower (about 1.8 times) peaks of analytes; these values can vary depending on the separation efficiency of the column. Carbon dioxide can also be effectively used as a makeup gas for the FID detector. The signal increase is comparable to that obtained with helium used as makeup (on average 40–50% depending on the carrier gas). When high sensitivity and high resolution are not required, CO2 can be an alternative carrier and makeup gas to helium under the same flow conditions. The paper also describes practical aspects related to the implementation of CO2 as a carrier and makeup gas in GC.

High-Performance Fluorine-Lean Thin Aromatic Hydrocarbon Membranes Based on Polyvinylidene Fluoride for Hydrogen Fuel Cells

The impeding ban on per- and polyfluoroalkyl substances (PFAS) prompted researchers to focus on hydrocarbon-based materials as constituents of next-generation proton exchange membranes (PEMs) for polymer electrolyte fuel cells (PEFCs). Here, we report on the fuel cell performance and durability of fluorine-lean PEMs prepared by the post-sulfonation of co-grafted α-methylstyrene (AMS) and 2-methylene glutaronitrile (MGN) monomers into preirradiated 12 µm polyvinylidene fluoride (PVDF) base film. The membranes were subjected to two distinctly different accelerated stress test (AST) protocols performed at open-circuit voltage (OCV): the US Department of Energy-similar chemical AST (90 °C, 30% relative humidity (RH), H2/air, 1 bara), developed originally for perfluoroalkylsulfonic acid (PFSA) membranes, and the high relative humidity AST (80 °C, 100% RH, H2/O2, 2.5 bara), designed for aromatic hydrocarbon membranes. We found that doping the grafted membranes with a metalated porphyrin antioxidant can simultaneously reduce membrane aging and improve fuel cell performance.

Influence of smoking method and anatomical location on the content of polycyclic aromatic hydrocarbons in Turopolje ham

In order to support a more sustainable breeding of the local Turopolje pig, the breed needs to be valorised through high added-value meat products, such as dry-cured and smoked Turopolje ham. To date, there are very few data on the quality and safety of Turopolje ham, including information on the content and distribution of potential contaminants such as polycyclic aromatic hydrocarbons (PAHs) from smoke. Hence, the aim of this study was to investigate the influence of smoking method (traditional or industrial) and anatomical site (M. biceps femoris - BF or M. semimembranosus - SM) on the content of PAHs in Turopolje ham. All hams (n=15) were produced the same way, differing only in smoking procedures; a traditional way above the firebox (group TRAD, n=5) or in the smoking chamber (group IND A - standard smoking, n=5 or B – 50 % reduced smoking, n=5). PAHs content (μg/kg) was determined and quantified by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Two-way analysis of variance was performed (GLM procedure of SAS) with fixed effects of smoking (S), muscle (M) and their interaction (SxM). Of the PAHs investigated, 14 compounds were detected. The results showed that TRAD hams had higher levels of anthracene (Ant), chrysene (Chr), benzo[b]fluoranthene (BbFA), benzo[a]pyrene (BaP), and the sum of benz[a]anthracene (BaA), Chr, BbFA and BaP (PAH 4) than hams from both A and B IND groups. TRAD hams had also higher content of acenaphthene (Acp), phenanthrene (Phen), pyrene (Py), BaA, and total PAHs than IND B hams. Compared to BF, SM muscle had higher content of several PAHs i.e. naphthalene (Nap), fluorine (Flu), Acp, Phen, Ant, fluoranthene (Flt), Py, BaA, benzo[k]fluoranthene (BkFA), benzo[ghi]perylene (BghiP), and also higher total PAH content. However, a significant SxM interaction was observed for Phen and Ant content which were higher only in SM muscle of TRAD hams. In conclusion, this study shows a marked influence of smoking method and anatomical site on the PAHs content in Turopolje hams, mainly in the form of lower BaP and the sum of PAH4 content in all chamber smoked hams compared to traditionally smoked hams and higher levels of light PAHs, some heavy PAHs and total PAH content in the more exposed SM compared to the inner BF muscle. Reduced smoking in IND hams did not affect BaP and the sum of PAH4 content, but reduced the content of some individual and total PAHs content. All IND hams and TRAD hams were below the maximum permitted level for BaP. However, two out of five hams from the TRAD group exceeded the limit for the sum of PAH4 (30 μg/kg) set by EU legislation for traditionally smoked meat products, indicating the need for stricter control of the traditional smoking process.

Unlocking the Potential: How Flavonoids Affect Angiogenesis, Oxidative Stress, Inflammation, Proliferation, Invasion, and Alter Receptor Interactions in Endometriosis

ABSTRACTEndometriosis, though not classified as a carcinogenic condition, shares features such as oxidative stress, migration, invasion, angiogenesis, and inflammation with tumor cells. This study aims to review the effects of flavonoids on these processes and their molecular mechanisms in preventing and treating endometriosis. A comprehensive review was conducted, involving a literature search in online databases using keywords like “endometriosis,” “endometrioma,” and “flavonoid.” Two authors screened the literature based on predefined criteria, and the selected studies were summarized in a structured data extraction table. Studies reviewed showed that various flavonoids impact key processes in endometriosis, including angiogenesis, inflammation, oxidative stress, and invasiveness. Flavonoids such as 2′,7'‐dichlorodihydrofluorescein diacetate (H2DCF‐DA), naringenin, apigenin, myricetin, 5,7‐dimethoxyflavone (DMF), chrysin, and 6,8‐diprenylorobol were found to induce oxidative stress. Xanthohumol, isoliquiritigenin, and luteolin demonstrated effects on angiogenesis. Apigenin, isoliquiritigenin, and luteolin exhibited anti‐inflammatory properties. Additionally, 3,6‐dihydroxyflavone, isoliquiritigenin, and naringenin displayed anti‐invasive activities. Flavonoid–receptor interactions further enhance their therapeutic potential in endometriosis management. Flavonoids such as nobiletin, chrysin, and daidzein modulate PPARγ and PPARα, reducing inflammation, promoting apoptosis, and improving lipid metabolism. These interactions regulate critical pathways in angiogenesis and immune responses. Additionally, flavonoids impact the aryl hydrocarbon receptor (AhR), with compounds like resveratrol inhibiting cell proliferation and cholesterol biosynthesis, further suppressing lesion growth. The ability of flavonoids like quercetin and kaempferol to antagonize NR4A1 leads to reduced cell proliferation and oxidative stress in endometriotic tissues. These findings offer insights into the mechanisms through which specific flavonoids modulate angiogenesis, inflammation, oxidative stress, and invasiveness in endometriosis. By targeting receptors such as PPARs, AhR, and NR4A1, flavonoids demonstrate the capacity to modulate both metabolic and inflammatory pathways, offering a multifaceted approach to managing endometriosis. Flavonoids can selectively target pathophysiologic molecules and pathways implicated in the condition. Consequently, leveraging the therapeutic attributes of flavonoids could lead to novel strategies for managing endometriosis.

Molecular Dynamics of CO₂ Stripping Oil on Quartz Surfaces

The CO2-enhanced oil recovery (EOR) technology has the dual significance of enhancing oil recovery and realizing carbon storage in onshore and offshore oil and gas exploitation. This study investigates the adsorption of crude oil components on quartz surfaces and the microscopic mechanisms of CO2 stripping from crude oil using molecular dynamics simulations. A four-component model representing C6H14, benzene, resins, and asphaltenes was constructed to simulate the oil phase, while the quartz surface model was created using Materials Studio. Simulations were conducted under different temperature conditions to understand the distribution and adsorption behavior of crude oil components, as well as the impact of CO2 on the oil film at pressures up to 10 MPa. The results indicate that the resin–asphaltene interactions are significantly weakened at elevated temperatures, affecting the adsorption capacity. Furthermore, CO2 stripping primarily extracts light components such as C6H14 and aromatic hydrocarbons, while heavy components remain in the oil phase. The highest extraction efficiency and expansion effect of CO2 were observed at 35 °C, demonstrating optimal conditions for enhanced oil recovery through CO2 flooding. These findings provide insights into the effective use of CO2 for crude oil extraction and its interactions with oil components on a quartz substrate, which is crucial for optimizing CO2-enhanced oil recovery operations.

Methods for Determining Polycyclic Aromatic Hydrocarbons (PAHs) in Milk: A Review

This review aims to compile and present information on polycyclic aromatic hydrocarbons (PAHs) in milk, their effects on human health, relevant legal regulations, and methods for their detection. PAHs are hazardous environmental pollutants that can accumulate in milk due to their lipophilicity and feed, water, and grass contamination. Also, high-temperature processing in the milk industry can contribute to their formation. PAHs are recognized for their carcinogenic, mutagenic, and teratogenic properties, posing significant risks to human health. Milk presents a unique analytical challenge as a complex matrix; the fats where hydrophobic PAHs tend to accumulate are “trapped” within the membranes of casein micelles. This complexity makes the extraction and analysis of PAHs more demanding than other food matrices. Developments in chromatographic techniques provide effective methods for detecting PAHs in milk, ensuring adherence to regulatory standards. The proper planning of research and the use of these techniques will lead to accurate results. This review focuses specifically on methods for extracting and isolating PAHs from milk, and instrumental methods for their detection and quantification. Such a review may be valuable for researchers looking for methods to analyze PAHs in milk and dairy products.

Removal of benzo[a]pyrene by a highly degradable microbial community immobilized by modified wheat straw biochar.

Benzo[a]pyrene (BaP), a high-molecular-weight polycyclic aromatic hydrocarbon (HMW-PAHs), is a prevalent organic pollutant. Due to various environmental factors, the viability and degradation capacity of PAHs-degrading bacteria in contaminated soil are significantly reduced. Therefore, it is imperative to maintain microbial activity and enhance degradation efficiency. This study aims to optimize BaP removal by utilizing biochar-immobilized BaP for the enhancement of microbial communities' degradative potential. The immobilization of modified wheat straw biochar (MWBC) significantly enhanced the removal efficiency of BaP by a highly efficient microbial community enriched from oil-contaminated soil, achieving a large removal efficiency of 75.18% for BaP (5-20mg/L) in a mineral salts medium in 12 d. The study also involved a detection of the species richness and intermediate metabolites of microbial community, as well as an assessment of the challenges and difficulties associated with managing real contaminated sites.

Fructo-oligosaccharides Alleviated Ulcerative Colitis via Gut Microbiota-Dependent Tryptophan Metabolism in Association with Aromatic Hydrocarbon Receptor Activation in Mice.

Fructo-oligosaccharide (FOS) is a typical prebiotic with intestinal health-promoting effects. Here, we explored the anticolitis activity of FOS and clarified the underlying mechanisms. Dextran sulfate sodium (DSS)-induced mice were gavaged with FOS (400 mg/kg) for 37 days, and administration of FOS alleviated DSS-induced colitis symptoms. Besides, FOS improved gut microbiota dysbiosis and modulated the intestinal microbiota-controlled tryptophan metabolic pathways. Targeted metabolomic results showed that FOS significantly increased the colonic levels of indole-3-acetic acid (IAA) and indole-3-propionic acid (IPA) and subsequently increased the expressions of aromatic hydrocarbon receptors (AhR) in the colon and further promoted the expressions of interleukin-22 (IL-22) and intestinal tight junction proteins in the colitis mice. These findings for the first time highlight a novel anticolitis mechanism of FOS by alleviating intestinal microbiota dysbiosis and modulating microbial tryptophan metabolism to promote IAA and IPA production for triggering AhR/IL-22 axis activation.

Structural Insight on the Selectivity of Calyx[4]Arene-Based Inhibitors of Mg2+-Dependent Atp-Hydrolases.

Located in plasma membranes, ATP hydrolases are involved in several dynamic transport processes, helping to control the movement of ions across cell membranes. ATP hydrolase acts as a transport protein, converting energy from ATP hydrolysis into transport molecules against their concentration gradients. In addition to energy metabolism and active transport, ATP hydrolase is essential for maintaining cellular homeostasis and cell function. This study focused on the domain architecture model of P-type ATPases, which participate in the reaction cycles of ATP hydrolysis carried out by membrane transport systems - Na+, K+-ATPase and Ca2+, Mg2+-ATPase. Targeted modulation of Na+, K+-ATPase and Ca2+, Mg2+-ATPase by unnatural drugs is of greatest interest due to the lack of known effectors. This new discovery presents a convenient model based on our recent experimental studies of the membrane structures and myocytes of the uterine smooth muscle, the myometrium. This current study strongly supports the fact that nanosized calix[4]arenes functionalised on the upper rings of the macrocycle with biologically active phosphonic acid fragments can serve as selective and potent inhibitors of cation-transporting electroenzymes. This is how we discovered that calix[4]arene of methylenebisphosphonic acid C-97 and calix[4]arene of bis-aminophosphonic acid C-107 selectively and effectively (I0.5 <100 nM) inhibit the activity of Mg2+, ATP-dependent electrogenic Na+ K+ plasma membrane pump. As drug discovery in the field of Mg2+-ATPase inhibitors is uncharted territory, basic research holds the key to explaining and predicting the mechanism of interaction and action of different classes of compounds. In light of the presented results, new calix[4]arene compounds can be used as potent inhibitors of Mg2+, ATP-dependent electrogenic ion pumps.

Enhanced Performance and Stability of CsPbBr3 Perovskite Solar Cells Using Trioctylphosphine Oxide Additive.

This study investigates the application of trioctylphosphine oxide (TOPO) and triphenylphosphine oxide (TPPO) as an additive to enhance the performance of all-inorganic CsPbBr3 perovskite solar cells (PSCs). The addition of TOPO and TPPO passivates surface defects, increases grain size, and reduces surface trap states, leading to better light absorption and accelerated carrier transport. These modifications lead to an optimized energy level distribution, resulting in a significant increase in power conversion efficiency from 5.14 to 9.21% with TOPO and from 5.14% to 7.28% with TPPO. Furthermore, the long alkyl chains in TOPO provide effective isolation from air and water, significantly enhancing device stability for over 2400 h without packaging. The findings demonstrate that oxygen phosphine additives with long alkane chains are more effective in improving PSCs than those with aromatic hydrocarbons, offering new insights for the use of passivators in perovskite solar cells.

Developmental Toxicity of Alkylated PAHs and Substituted Phenanthrenes: Structural Nuances Drive Diverse Toxicity and AHR activation

Polycyclic aromatic hydrocarbons (PAHs) are a diverse class of chemicals that occur in complex mixtures including parent and substituted PAHs. To understand the hazard posed by complex environmental PAH mixtures, we must first understand the structural drivers of activity and mode of action of individual PAHs. Understanding the toxicity of alkylated PAHs is important as they often occur in higher abundance in environmental matrices and can be more biologically active than their parent compounds. 104 alkylated PAHs were screened from 11 different parent compounds with emphasis on substituted phenanthrenes and their structurally dependent toxicity differences. Using a high-throughput early life stage zebrafish assay, embryos were exposed to concentrations between 0.1 to 100 μM and assessed for morphological and behavioral outcomes. The aryl hydrocarbon receptor (AHR) is often implicated in the toxicity of PAHs and the induction of cytochrome P4501A (cyp1a) is an excellent biomarker of Ahr activation. Embryos were evaluated for cyp1a induction using a fluorescence reporter line. Alkyl and polar phenanthrene derivatives were further assessed for spatial cyp1a expression and Ahr dependence of morphological effects. In the alkyl PAH screen 35 (33.7%) elicited a morphological or behavioral response and of those 23 (65%) also induced cyp1a. 31 (29.8%) of the chemicals only induced cyp1a. Toxicity varied substantially in response to substitution location, the amount of ring substitutions and alkyl chain length. Cyp1a induction varied by parent compound group and was a poor indicator of morphological or behavioral outcomes. Polar phenanthrenes were more biologically active than alkylated phenanthrene derivatives and their toxicity was not dependent upon the Ahr2, Ahr1a or Ahr1b when tested individually, despite cyp1a induction by 50% of polar phenanthrenes. Our results demonstrated that induction of cyp1a did not always correlate with PAH toxicity or Ahr dependence and that the type and location of phenanthrene substitution determined potency.

Chemical Composition and Toxicity of Water-Soluble Fractions of Oil Samples from the Extensive Spill in Northeast Brazil.

This study evaluated the effects of water-soluble fractions (WSF) of stranded oil sampled from the beaches of Trancoso and Massarandupió (Bahia, Brazil) following a mysterious oil spill along Brazil's northeast coast (2019-2020). The samples were characterized for aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) and tested for chronic toxicity in the embryo-larval stages of the sea urchin Echinometra lucunter. The WSFs contained high levels of PAHs, some of which were above the acceptable levels for water in Brazil, and toxicity to sea urchin embryos tended to occur at higher concentrations.

Biodegradation of polycyclic aromatic hydrocarbons with enterobacter asburiae

Polycyclic Aromatic Hydrocarbons (PAHs) pollution has been found to be toxic, mutagenic, carcinogenic, teratogenic, and immunotoxicogenic. Naphthalene, Anthracene, and Fluorene are among the polycyclic aromatic hydrocarbons (PAHs) that are frequently detected in wastewater from biomass gasification and refineries. In this study, industrial waste water samples were collected from three sites located in Kafr El-Sheikh Governorate, Egypt and showed presence of PAHs in different concentration varying from 0.42 to 253.1 ppb. This study's findings included the isolation and identification of Enterobacter asburiae the most proficient bacterial isolate capable of biodegrading PAHs among other 7 studied bacterial isolates. Enterobacter asburiae strain No. 1 showed the ability to biologically degrade approximately 79 %, 89.7 % and 82.8 % of Naphthalene, Fluorene and Anthracene active ingredients respectively. The results of toxicity assessment showed that PAHs byproducts after 14 days of incubation had no toxicity; consequently, there was no antibacterial activity detected against B. subtilis as a test organism. Such biological approaches used in this study can be further applied in various polluted sites to get rid of ubiquitous organic pollutants.