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BackgroundThe Atribacterota are widely distributed in the subsurface biosphere. Recently, the first Atribacterota isolate was described and the number of Atribacterota genome sequences retrieved from environmental samples has increased significantly; however, their diversity, physiology, ecology, and evolution remain poorly understood.ResultsWe report the isolation of the second member of Atribacterota, Thermatribacter velox gen. nov., sp. nov., within a new family Thermatribacteraceae fam. nov., and the short-term laboratory cultivation of a member of the JS1 lineage, Phoenicimicrobium oleiphilum HX-OS.bin.34TS, both from a terrestrial oil reservoir. Physiological and metatranscriptomics analyses showed that Thermatribacter velox B11T and Phoenicimicrobium oleiphilum HX-OS.bin.34TS ferment sugars and n-alkanes, respectively, producing H2, CO2, and acetate as common products. Comparative genomics showed that all members of the Atribacterota lack a complete Wood-Ljungdahl Pathway (WLP), but that the Reductive Glycine Pathway (RGP) is widespread, indicating that the RGP, rather than WLP, is a central hub in Atribacterota metabolism. Ancestral character state reconstructions and phylogenetic analyses showed that key genes encoding the RGP (fdhA, fhs, folD, glyA, gcvT, gcvPAB, pdhD) and other central functions were gained independently in the two classes, Atribacteria (OP9) and Phoenicimicrobiia (JS1), after which they were inherited vertically; these genes included fumarate-adding enzymes (faeA; Phoenicimicrobiia only), the CODH/ACS complex (acsABCDE), and diverse hydrogenases (NiFe group 3b, 4b and FeFe group A3, C). Finally, we present genome-resolved community metabolic models showing the central roles of Atribacteria (OP9) and Phoenicimicrobiia (JS1) in acetate- and hydrocarbon-rich environments.ConclusionOur findings expand the knowledge of the diversity, physiology, ecology, and evolution of the phylum Atribacterota. This study is a starting point for promoting more incisive studies of their syntrophic biology and may guide the rational design of strategies to cultivate them in the laboratory. Video Abstract.

The paper presents the application of the multi-layer perceptron regressor model for predicting the parameters of positron annihilation lifetime spectra using the example of alkanes in the solid phase. Good agreement of calculation results was found when the approach is compared with the commonly used methods, e.g., LT. The presented method can be used as an alternative quick and accurate tool for the decomposition of positron annihilation lifetime spectroscopy (PALS) spectra in general. The advantages and disadvantages of this new method are discussed. We show the preliminary results where the trained network can give better outcomes than the results yielded by programs based on an analysis of a single PALS spectrum. [ABSTRACT FROM AUTHOR]

Carbonylation reactions have been widely used to construct carbonyl-containing molecules or carbon enhancement reactions, which are mostly catalyzed by noble metals (Pd, Rh, Ru, Ir). In this review, we introduce the copper-catalyzed carbonylation reactions that have been developed in our group. Diverse reactions have been developed using various substrates, including the carbonylation of C–H activated alkanes, the difunctionalization of unsaturated C–C bonds, and the carbonylation of alkyl halides via the radical pathway. 1 Introduction 2 Cu-Catalyzed Carbonylation of C(sp3)–H Bonds 3 Cu-Catalyzed Carbonylative Difunctionalization of Unsaturated Bonds 4 Cu–X (H or B) Mediated Acylation of Unsaturated Bonds with Electrophiles 5 Cu–X (H or B) Mediated Carbonylation of Unsaturated Bonds 6 Cu-Catalyzed Carbonylation of Alkyl Halides 7 Other Types of Copper-Catalyzed Carbonylation Reactions 8 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

Alkane dehydrogenation to alkene represents a promising alternative route for conventional petroleum cracking processes heavily reliant on fossil resources. This Concept outlines the latest advancements of novel alkane dehydrogenation routes that offer potential solutions to intrinsic problems existing in routine direct dehydrogenation or oxidative dehydrogenation reactions, including CO2 assisted alkane dehydrogenation, chemical looping alkane oxidative dehydrogenation, dual‐path dehydrogenation and auto‐accelerated multiple alkane dehydrogenation route. These novel reaction routes exhibit unique advantages in enhancing the activity, selectivity and stability of the alkane dehydrogenation reaction system. The rational design of novel catalysts and proper choice of the reaction condition that well‐fitted these reaction routes is the key for achieving highly efficient and stable alkane dehydrogenation process. These present examples in this manuscript also highlight the importance of fundamental in‐depth understandings on the mechanism and structure‐function relations, which is the foundation for developing novel alkane dehydrogenation routes for practical applications. [ABSTRACT FROM AUTHOR]

Taking Gonghe oil shale as raw material, the rapid pyrolysis experiment was carried out using the Py-GC/MS device under different atmospheres. The effects of different pyrolysis atmospheres on the rapid pyrolysis products of Gonghe oil shale were studied. The results show that the H2 atmosphere can not only increase the content of saturated hydrocarbons and reduce the content of unsaturated hydrocarbons but also reduce the content of oxygen-containing heterocyclic compounds. This may be because more H free radicals under the H2 atmosphere are produced to react with the free radical fragments formed by kerogen decomposition. The coupling between H free radicals and free radical fragments can prevent the polymerization among macromolecular free radicals and inhibit the generation of heavy byproducts, which can promote the kerogen pyrolysis and increase the release of volatile matter. In addition, the pyrolysis atmosphere is conducive to the deoxygenation of oxygen-containing heterocyclic compounds to a certain extent. [ABSTRACT FROM AUTHOR]

In this study, a novel approach for the tertiary α‐alkylation of ketones using alkanes with electron‐deficient C─H bonds is presented, employing a synergistic catalytic system combining inexpensive copper salts with aminocatalysis. This methodology addresses the limitations of traditional alkylation methods, such as the need for strong metallic bases, regioselectivity issues, and the risk of over alkylation, by providing a high reactivity and chemoselectivity without the necessity for pre‐functionalized substrates. The dual catalytic strategy enables the direct functionalization of C(sp3)─H bonds, demonstrating remarkable selectivity in the presence of conventional C(sp3)─H bonds that are adjacent to heteroatoms or π systems, which are typically susceptible to single‐electron transfer processes. The findings contribute to the advancement of alkylation techniques, offering a practical and efficient route for the construction of C(sp3)─C(sp3) bonds, and paving the way for further developments in the synthesis of complex organic molecules. [ABSTRACT FROM AUTHOR]

In mass production, injection molding plays a vital role in manufacturing various parts with complex settings. As perfluoroalkoxy alkane (PFA) injection‐molded products are widely used in immersion system, dimensional quality needs more attention. However, there is limited research on the dimension defects of PFA injection‐molded products. This study focused on the influence of mold design and process parameters on PFA part shrinkage, using mold flow simulation and orthogonal testing separately. Several gate locations and sizes were simulated to minimize shrinkage in mold design. Displacements varied with gate locations, and shrinkage decreased with larger gate sizes. The Taguchi method analyzed process parameters' impact on shrinkage. The results indicated that the injection rate had the most significant effect on the shrinkage of tube length, while melt temperature, holding pressure, and screw speed affected the shrinkage of tubes' outside diameter. Different flow directions exhibited variance in shrinkage. Using max–min normalization, the two shrinkage values reached 0.00972, whereas the smallest value obtained in the orthogonal experiment was 0.1545 in run 3. Thus, optimizing mold design and process parameters were two effective methods to reduce shrinkage. This study reduced shrinkage and improved the quality of PFA injection molding parts for semiconductor systems. [ABSTRACT FROM AUTHOR]

The chemically inert nature of fully saturated hydrocarbon backbones endows vinyl polymers with desirable durability, but it also leads to their significant environmental persistence. Enhancing the sustainability of these materials requires a pivotal yet challenging shift: transforming the inert backbone into one that is degradable. Here, we present a versatile platform for mechanochemically editing the fully saturated backbone of vinyl polymers towards degradable polymer chains by integrating cyclobutene‐fused succinimide (CBS) units along backbone through photo‐iniferter reversible addition‐fragmentation chain‐transfer (RAFT) copolymerization. Significantly, the evenly insertion of CBS units does not compromise thermal or chemical stability but rather offers a means to adjust the properties of polymethylacrylate (PMA). Meanwhile, reactive acyclic imide units can be selectively introduced to the backbone through mechanochemical activation (pulse ultrasonication or ball‐milling grinding) when required. Subsequent hydrolysis of the acyclic imide groups enables efficient degradation, yielding telechelic oligomers. This approach holds promise for inspiring the design and modification of more environmentally friendly vinyl polymers through backbone editing. [ABSTRACT FROM AUTHOR]

Background: The prevalence of sarcopenia is increasing in worldwide with accelerated aging process. The high dietary protein intakes are associated with improved muscle mass and strength especially in Asian countries. However, there are few researches on amino acid levels or mechanism exploration. We conducted a case-control study to explore the amino acid metabolic characteristics and potential mechanism of elderly women with sarcopenia using targeted amino acid metabolomics approach combined with an analysis of dietary intake. Methods: For our case-control study, we recruited women (65–75 y) from a Shanghai community with 50 patients with sarcopenia and 50 healthy controls. The consensus updated by the Asian Working Group on Sarcopenia in 2019 was used to screening for sarcopenia and control groups. We collected fasting blood samples and evaluated dietary intake. We used the amino acid-targeted metabolomics by ultra performance liquid chromatography tandem mass spectrometry to identify metabolic differentials between the case and control groups and significantly enriched metabolic pathways. Results: The case (sarcopenia) group had a lower intake of energy, protein, and high-quality protein (P < 0.05) compared to the control (healthy) group. We identified four differential amino acids: arginine (P < 0.001) and cystine (P = 0.003) were lower, and taurine (P = 0.001) were higher in the case group. Conclusion: Low levels of arginine in elderly women are associated with a higher risk of sarcopenia. [ABSTRACT FROM AUTHOR]

The decarboxylative oxygenation of readily available carboxylic acids as well as the oxidation of alkenes and alkanes has been accomplished through visible light using g‐C3N4 as a robust and recyclable catalyst. The scalable protocol furnishes an array of aldehydes and ketones under mild reaction conditions, requiring only molecular oxygen as an oxidant. Notably, no addition of stochiometric amounts of base is required, and furthermore, the reaction proceeds efficiently open to the air. [ABSTRACT FROM AUTHOR]

To clarify the growth mechanisms of Rhodococcus in the alkane phase, we measured oxygen utilization in the alkane phase. The results showed that dissolved oxygen decreased significantly when viable cells were present in the alkane phase. The findings suggested that Rhodococcus strains can grow in alkanes and utilize the resident dissolved oxygen. [ABSTRACT FROM AUTHOR]

Conventional Fenton chemical oxidation was more difficult to directly oxid all alkanes of long, mid and short-chain alkanes in oil-contaminated soil. To investigate the direct and fast oxidation mechanism of all alkanes in the soil by the fast oxidation group using two different soils for the direct oxidation experiments. The results showed that the hydrophilic Fe-SOM rich in hydrophilic groups could directly oxidize all alkanes in the soil with a high removal rate of total petroleum hydrocarbons (TPH) (59.0%–72.5%). Similarly, for the oxidation of long-chain alkanes (C23-C30), the fast oxidation group in which the hydrophilic Fe-SOM was located had higher removal rates (52%-64%). Regarding long chain oxidation per unit hydroxyl radicals (•OH) intensity, the fast oxidation group was significantly higher than the slow oxidation group (1.3–4.2 times). The results revealed a well-linear fit (r2 = 0.97, 0.81) for total iron and FeOOH with hydrophilic groups such as C=O and C-O-C in the fast oxidation group regarding content. Hydrophilic Fe-SOM enabled the rapid decomposition (51% − 88%) of H2O2 in the presence of hydrophilic promoters such as humic acid (49%−79%). The hydrophilic groups and hydrophilic promoters made the •OH generated by decomposition collide and react with pollutants rapidly to maximize the •OH in the liquid phase. The TPH removal efficiency per the unit intensity of •OH in the fast oxidation group was 3.74 times higher than in the slow oxidation group. The long-chain removal efficiency was 4.2 times higher than that in the slow oxidation group. The above results indirectly proved that the oxidation reaction in the fast oxidation group occurred at the petroleum pollutants and also demonstrated that the technology is an in situ oxidation technology. This technology can directly oxidize all petroleum hydrocarbons in the soil and has excellent engineering application value. [ABSTRACT FROM AUTHOR]

In order to in-depth investigate the influence of sensitive group-fractions affecting the formation of volatile products on the efficient thermal conversion of Buton oil sand bitumen (OSB), the average structural parameters of aromatics (Ar), resins (Re) and their sub-fractions as sensitive group-fractions were analyzed at the near-molecular level firstly. Subsequently, the thermal-cracking characteristics of these sensitive fractions and the determination of the specific sensitive group-fraction that affected most significantly on the volatiles generation during thermal upgrading process of Buton OSB were investigated via TG–FTIR. The results indicated that thermal-cracking behaviors of Ar, Re and their sub-fractions were disparate on the grounds of their thermal-cracking characteristic parameters and the release laws of detected gaseous products. A novel analysis method was proposed to determine the most sensitive group-fraction based on the variation and its rangeability of thermal mass loss rate of these group-fractions at various heating rate and temperature. The sensitive group-fraction was inclined to be heavier with the incremental temperature at the same heating rate. Finally, the formation behaviors of the thermal-cracking volatile products of sensitive group-fractions were explored by Py–GC/TOF–MS. It was found that the relative content and carbon number distribution of various classes of volatile products (i.e., alkenes, alkanes, diolefins and aromatics) for sensitive group-fractions showed the different changing trends due to the diversity of composition and structure of sensitive group-fractions influencing the reaction pathway. As the sensitive group-fractions tended to be heavier from L-Ar to H-Re, the sensitive group-fraction had more significant contribution to the formation of alkanes and aromatics in volatile products of OSB yet the lessened influence on the generation of alkenes products. [ABSTRACT FROM AUTHOR]

To mitigate global carbon emissions, utilizing bio-based oils instead of petroleum for biodiesel production has emerged as a viable strategy. However, the development of efficient catalysts for the mild conversion of fatty acid esters (the mainly compounds of oils or fats) into diesel-range alkanes remains challenging due to the low reactivity of carbonyl group in esters. Herein, we report an efficient catalyst system for the hydrodeoxygenation of fatty acid esters into diesel-range alkanes under mild conditions over the RemNin@SiO2 catalyst. The catalyst containing a Re/Ni molar ratio of 1.0 showed the best catalytic performance, a 100% conversion and 96.3% selectivity towards n-octadecane/n-heptadecane(C18/C17) were obtained when using the methyl stearate as model compound under mild condition (170 °C and 2.5 MPa H2 pressure), surpassing the catalytic performance of the most catalytic systems reported so far. Characterization results showed that the excellent catalytic performance of the RemNin@SiO2 catalyst was mainly attributed to the formation of ReNi alloy, which enhanced the interaction between the catalyst and the oxygen atom of carbonyl group of esters, thereby activating the carbonyl group and promoting the deoxygenation of fatty acid esters under mild conditions. In addition, the synthesized Re1Ni1@SiO2 bimetallic catalyst has good stability, and after four cycles, the catalyst still exhibits high catalytic performance with above 90% alkane conversion. Re1Ni1@SiO2 catalyzed the hydrodeoxygenation of Methyl Stearate towards alkanes (C18/C17) under mild conditions. [ABSTRACT FROM AUTHOR]

Methanogenic hydrocarbon degradation can be carried out by archaea that couple alkane oxidation directly to methanogenesis, or by syntrophic associations of bacteria with methanogenic archaea. However, metagenomic analyses of methanogenic environments have revealed other archaea with potential for alkane degradation but apparent inability to form methane, suggesting the existence of other modes of syntrophic hydrocarbon degradation. Here, we provide experimental evidence supporting the existence of a third mode of methanogenic degradation of hydrocarbons, mediated by syntrophic cooperation between archaeal partners. We collected sediment samples from a hot spring sediment in Tengchong, China, and enriched Hadarchaeota under methanogenic conditions at 60 °C, using hexadecane as substrate. We named the enriched archaeon Candidatus Melinoarchaeum fermentans DL9YTT1. We used 13C-substrate incubations, metagenomic, metatranscriptomic and metabolomic analyses to show that Ca. Melinoarchaeum uses alkyl-coenzyme M reductases (ACRs) to activate hexadecane via alkyl-CoM formation. Ca. Melinoarchaeum likely degrades alkanes to carbon dioxide, hydrogen and acetate, which can be used as substrates by hydrogenotrophic and acetoclastic methanogens such as Methanothermobacter and Methanothrix. Methanogenic hydrocarbon degradation can be carried out by archaea either by coupling alkane oxidation directly to methanogenesis, or in syntrophic associations with bacteria. Here, the authors provide experimental evidence supporting that methanogenic degradation of hydrocarbons can also be mediated by syntrophic cooperation between archaeal partners. [ABSTRACT FROM AUTHOR]

This scientific review delves into the innovative realm of polyolefins/light alkanes valorization through their catalytic dehydrogenation employing pincer-ligated iridium organometallic complexes. These widely studied catalysts exhibit outstanding properties, although the intrinsic characteristics of homogeneous catalysis (such as challenging product–catalyst separation, poor applicability to continuous-flow processes and low recyclability) limit their activity and industrial application, as well as their thermal stability. Through the immobilization of complexes on inorganic supports, these downsides have been bypassed, harnessing the true potential of these catalysts, affording more selective and stable catalysts in addition to facilitating their implementation in industrial processes. The findings described herein contribute to the advancement in the understanding of catalytic processes in hydrocarbon transformations, offering promising avenues for sustainable and selective production of valuable chemical intermediates from readily available feedstocks. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations for calculation of the contact angle of surface nanodroplets and solid–liquid surface tension γ sl of linear triocontane (C 30 , left image) and four of its branched isomers (centre image is for 2,6,13,17, tetrapropyloctadecane (C 18 (C 3) 4)) are used to calculate line tension τ. The results reveal (left plots) that γ sl and line tension τ depend on surface oleophilicity/oleophobicity and molecular degree of branching (DB*). [Display omitted] • Developed a novel MD calculation method of surface nanodroplet line tension (τ). • Calculated Solid-liquid surface tension γ sl of linear and branched liquid alkanes, showed deviation from Young equation. • γ sl and τ signs depend on surface wettability, and their magnitude reduce with increased branching. • On the oleophilic surface, positive line tensions in the order of 10-10 for all alkanes. • On the oleophobic surface, τ is two orders of magnitude lower for branched alkanes. Surface nanodroplets have important technological applications. Previous experiments and simulations have shown that their contact angle deviates from Young's equation. A modified version of Young's equation considering the three-phase line tension (τ) has been widely used in literature, and a wide range of values for τ are reported. We have recently shown that molecular branching affects the liquid–vapour surface tension γ lv of liquid alkanes. Therefore, the wetting behaviour of surface nanodroplets should be affected by molecular branching. This study conducted molecular dynamics (MD) simulations to gain insight into the wetting behaviour of linear and branched alkane nanodroplets on oleophilic and oleophobic surfaces. We aim to examine the Young equation's validity and branching's effect on fundamental properties, including solid–liquid surface tension γ sl and line tension τ. The simulations were performed on a linear alkane, triacontane (C 30 H 62), as well as four of its branched isomers: 2,6,13,17-tetrapropyloctadecane,2,6,9,10,13,17-hexaethyloctadecane, 2,5,7,8,11,12,15-heptaethylhexadecane and 2,3,6,7,10,11-hexapropyldodecane. Nanodroplets with a diameter of approximately 15 nm were released onto the surfaces, and their contact angles were measured. Additionally, using a novel approach, the solid–liquid surface tension (γ sl), the validity of Young's equation and line tension for all alkane and surface combinations are determined. It was discovered that the calculated γ sl , deviated from the theoretical γ sl , Young predicted from Young's equation for all alkanes on oleophilic surfaces. However, this deviation was minimal for branched alkanes on the oleophobic surfaces but more significant for the linear alkane. The findings indicated that γ sl < 0 for oleophilic surfaces and γ sl > 0 for oleophobic surfaces. Moreover, it was observed that | γ sl | was lower for branched molecules and decreased as branching increased. Line tension values were then determined through a novel method, showing τ was positive for oleophilic surfaces ranging from 1.30 × 10-10 to 6.27 × 10-11N. On an oleophobic surface, linear alkane shows a negative line tension of −1.15 × 10-10N and branched alkanes up to two orders of magnitude lower values ranging from −2.09 × 10-12 to 2.43 × 10-11N. Line tension values between −1.15 × 10-10 and + 1.1 × 10-10N are calculated for various linear alkane and surface combinations. These findings show the dependence of line tension on the contact angle and branching, demonstrating that for linear alkanes, τ is significant, whereas, for branched alkanes, line tension is smaller or negligible for large contact angles. [ABSTRACT FROM AUTHOR]

Introduction: ALZ-801/valiltramiprosate is a small-molecule oral inhibitor of beta amyloid (Aβ) aggregation and oligomer formation being studied in a phase 2 trial in APOE4 carriers with early Alzheimer's disease (AD) to evaluate treatment effects on fluid and imaging biomarkers and cognitive assessments. Methods: The single-arm, open-label phase 2 trial was designed to evaluate the effects of the ALZ-801 265 mg tablet taken twice daily (after 2 weeks once daily) on plasma fluid AD biomarkers, hippocampal volume (HV), and cognition over 104 weeks in APOE4 carriers. The study enrolled subjects aged 50–80 years, with early AD [Mini-Mental State Examination (MMSE) ≥ 22, Clinical Dementia Rating-Global (CDR-G) 0.5 or 1], apolipoprotein E4 (APOE4) genotypes including APOE4/4 and APOE3/4 genotypes, and positive cerebrospinal fluid (CSF) AD biomarkers or prior amyloid scans. The primary outcome was plasma p-tau181, HV evaluated by magnetic resonance imaging (MRI) was the key secondary outcome, and plasma Aβ42 and Aβ40 were the secondary biomarker outcomes. The cognitive outcomes were the Rey Auditory Verbal Learning Test and the Digit Symbol Substitution Test. Safety and tolerability evaluations included treatment-emergent adverse events and amyloid-related imaging abnormalities (ARIA). The study was designed and powered to detect 15% reduction from baseline in plasma p-tau181 at the 104-week endpoint. A sample size of 80 subjects provided adequate power to detect this difference at a significance level of 0.05 using a two-sided paired t-test. Results: The enrolled population of 84 subjects (31 homozygotes and 53 heterozygotes) was 52% females, mean age 69 years, MMSE 25.7 [70% mild cognitive impairment (MCI), 30% mild AD] with 55% on cholinesterase inhibitors. Plasma p-tau181 reduction from baseline was significant (31%, p = 0.045) at 104 weeks and all prior visits; HV atrophy was significantly reduced (p = 0.0014) compared with matched external controls from an observational Early AD study. Memory scores showed minimal decline from baseline over 104 weeks and correlated significantly with decreased HV atrophy (Spearman's 0.44, p = 0.002). Common adverse events were COVID infection and mild nausea, and no drug-related serious adverse events were reported. Of 14 early terminations, 6 were due to nonserious treatment-emergent adverse events and 1 death due to COVID. There was no vasogenic brain edema observed on MRI over 104 weeks. Conclusions: The effect of ALZ-801 on reducing plasma p-tau181 over 2 years demonstrates target engagement and supports its anti-Aβ oligomer action that leads to a robust decrease in amyloid-induced brain neurodegeneration. The significant correlation between reduced HV atrophy and cognitive stability over 2 years suggests a disease-modifying effect of ALZ-801 treatment in patients with early AD. Together with the favorable safety profile with no events of vasogenic brain edema, these results support further evaluation of ALZ-801 in a broader population of APOE4 carriers, who represent two-thirds of patients with AD. Trial Registration: https://clinicaltrials.gov/study/NCT04693520. [ABSTRACT FROM AUTHOR]

The paper presents the results of cracking of extra-heavy oil in the pore space of a coal additive in a nitrogen atmosphere and in a subcritical aqueous fluid at a temperature of 365°C and a pressure of 17 MPa. The coal additive consisted of an amorphous carbon phase forming a developed microporous structure. An analysis using scanning electron microscopy and adsorption porometry established that a vapor- air modification of the coal additive changes its surface relief and leads to the development of a micro- and mesopore structure. The intrapore space of the modified coal additive contains 38.6 vol % mesopores with a specific surface area of 172 m2/g. The final products of extra-heavy oil cracking with the proposed coal additive are characterized by an increase in the content of saturated and aromatic hydrocarbons, as well as by an almost complete absence of asphaltenes. The largest hydrocarbon yield was observed during extra-heavy oil cracking in a nitrogen atmosphere. In experiments, asphaltene conversion processes are observed due to the destruction of C–C, C–N, and C–O bonds with the formation of low-boiling compounds and high-carbon substances. The largest yield of aromatic hydrocarbons is observed during cracking in a subcritical aqueous fluid, with the yield of liquid products being reduced due to intensive gas formation. The hydrocarbon composition of gases is dominated by lower alkanes, which indicates the destruction of C–C bonds. [ABSTRACT FROM AUTHOR]

A [(POCN)Ir(H)(OAc)] complex bearing an iminophosphinite pincer ligand was synthesized. The complex showed catalytic transfer dehydrogenation of various linear and cyclic alkanes with reasonable conversions and a maximum TON of 400 for n‐octane. A catalytic isomerization of 1‐octene to yield internal octenes was also possible. It is notable that the catalyst could perform catalytic transfer dehydrogenation even at a temperature of 100 °C with a TON of 100. [ABSTRACT FROM AUTHOR]

The development of energy storage materials is crucial for effective energy management. In this study, we present the creation of a composite material comprising polypropylene (PP) aerogel, paraffin, and multi‐walled carbon nanotubes (MWCNTs) as a phase change material (PCM). Our process begins with the dissolution of PP granules, serving as the foundational step. Subsequently, various antisolvents are systematically employed to induce the formation of PP gels. The process culminates in the fabrication of aerogels through the established freeze‐drying technique. Importantly, our examination of porosity highlights the significant impact of antisolvent selection on the pore structure and specific surface area of the resulting aerogels. Our weight measurements demonstrate the remarkable capacity of the lightweight PP aerogel, characterized by substantial porosity and inherent hydrophobicity, to adsorb paraffin, capturing up to five times its weight. These findings are substantiated through structural analyses, including Fourier‐transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD). Thermal analysis of the PP/PCM/MWCNTs composites reveals the achievement of the highest enthalpy, reaching 125 J g−1, representing a modest 13% reduction compared to pure paraffin. Furthermore, all samples exhibit exceptional thermal stability even after 50 thermal cycles. Notably, Xenon flash analysis (XFA) shows an approximate 800% increase in thermal conductivity compared with pure paraffin and a substantial 35% increase compared to PP/paraffin composites. In conclusion, our lightweight aerogel‐based PCM demonstrates great promise for various thermal management applications. Highlights: Cost‐effective PP aerogel has a great potential for hosting paraffin as PCM.The type of antisolvent could have a huge effect on PP aerogel's structure.PP aerogel/Paraffin/MWCNT could effectively enhance thermal conductivity.Available PP/Paraffin/MWCNT has a great potential for PCM applications. [ABSTRACT FROM AUTHOR]

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The changes and transformation laws of intermediate liquid-phase products during the anaerobic degradation of lignite by sulfate-reducing bacteria in the formation of hydrogen sulfide play an important role in supplementing and improving the existing theories on the genesis of hydrogen sulfide gas in coal mines. In this paper, H2S gas and key intermediate liquid-phase products produced during the anaerobic degradation of lignite by sulfate-reducing bacteria were detected and analyzed by gas chromatography and gas chromatography-mass spectrometry. The results showed that the process of hydrogen sulfide production from lignite degradation by sulfate-reducing bacteria can be roughly divided into four stages: slow production phase, rapid growth phase, steady production phase, and slight decline phase. In this reaction system, the SO42− concentration showed a decreasing trend, the pH value showed an increasing trend, and the ORP value decreased and then slightly increased with time. Ten volatile component types were detected during the experiment: straight-chain alkanes, branched-chain alkanes, alcohols, aldehydes, ketones, olefins, amines, lipids, acids and phenols. The key components in the intermediate liquid phase products were straight chain alkanes, straight chain alkanes, acids, alcohols, phenols and amines. PAHs, alkanes, and phenols are closely related to H2S production, while amides stimulate nitrogen production. The process is divided into three stages: hydrolysis stage, H2S gas production stage, and decay stage. Liquid-phase intermediates play an important role in the formation process of coal mine BSR hydrogen sulfide and the mechanism of coal mine H2S genesis. [ABSTRACT FROM AUTHOR]

We present a computer simulation study of the aggregation and ordering of short alkane chains using a united atom model description. Our simulation approach allows us to determine the density of states of our systems and, from those, their thermodynamics for all temperatures. All systems show a first order aggregation transition followed by a low-temperature ordering transition. For a few chain aggregates of intermediate lengths (up to N = 40), we show that these ordering transitions resemble the quaternary structure formation in peptides. In an earlier publication, we have already shown that single alkane chains fold into low-temperature structures, best described as secondary and tertiary structure formation, thus completing this analogy here. The aggregation transition in the thermodynamic limit can be extrapolated in pressure to the ambient pressure for which it agrees well with experimentally known boiling points of short alkanes. Similarly, the chain length dependence of the crystallization transition agrees with known experimental results for alkanes. For small aggregates, for which volume and surface effects are not yet well separated, our method allows us to identify the crystallization in the core of the aggregate and at its surface, individually. [ABSTRACT FROM AUTHOR]

Combining molecular imprinting technology with electrostatic spinning technology, a molecularly imprinted nanofiber membrane material with memory and recognition of specific imprinted molecules is thus produced. It has the advantages of high efficiency, reusability, easy amplification, and simple operation. In this study, alkane molecularly imprinted nanofibrous membranes are prepared as a carrier for immobilize Bacillus cereus LY‐1 for the degradation of diesel in oil–water system. The adsorption capacity of the molecularly imprinted material for diesel oil with n‐decyl alcohol as the template molecule reach 120.25 mg g−1, the adsorption capacity of alkane molecularly imprint nanofiber membrane prepared using polyvinyl alcohol (PVA) as the membrane substrate material is 41.37 mg g−1. After 4 days, the immobilized LY‐1 cells eliminate roughly 80.7% of the diesel at a starting concentration of 3 g L−1. The results show that imprinted structures in MINM enhance degradation by loaded microorganisms. [ABSTRACT FROM AUTHOR]

Herein, we present a CuI-dimer, [CuI{Ph2PC6H4C(O)NC6H4PPh2-o}]2, which catalyzed direct C(sp3)–H homocoupling of benzyl and cycloalkane derivatives with excellent yields and regio-selectivity. The method is very simple and tolerates various functionalities. Synergistic metal–ligand cooperativity was observed in Cu–N bond cleavage and protonation of nitrogen, and facilitates a bifunctional pathway, minimising the free energy corrugation for catalytic intermediates. [ABSTRACT FROM AUTHOR]

The dehydrogenation of alkanes is a critical process to enable olefin upcycling in a circular economy. A suitable selective catalyst is required in order to avoid demanding reaction conditions and ensure the activation of the C−H bond rather than breaking the C−C bond, which is the weaker of the two. Herein, using periodic density functional theory, we have investigated the dehydrogenation of n‐pentane (as a model compound) on Pt and Ru surface catalysts. The results show that the first dehydrogenation occurs through the dissociative adsorption of the C−H bond, resulting in pentyl and H intermediates on the metal surfaces. A successive dehydrogenation creates pentene via a hydride di‐σ state, leaving the abstracted hydrogen atoms on the metal surfaces. In agreement with recent experiments, Pt and Ru catalysts show a similar reactivity trend: pentane dehydrogenation yields pent‐1‐ene and pent‐2‐ene. The simulations reveal that the 1st C−H dissociation is the rate‐determining step, whereas the double‐bonded alkenes (pent‐1‐ene and pent‐2‐ene) are formed due to fast successive dehydrogenation processes. Pt favors the formation of pent‐1‐ene, whereas Ru favors the formation of pent‐2‐ene. [ABSTRACT FROM AUTHOR]

Background: Taurine, an amino acid abundantly found in the brain and other tissues, has potential neuroprotective properties. Alzheimer's disease (AD) is a commonly occurring type of dementia, which becomes more prevalent as people age. This experiment aimed to assess the neuroprotective effects of taurine on SH-SY5Y cells by examining its impact on Dihydrotestosterone (DHT), Dihydroprogesterone (DHP), as well as the expression of miRNA-21 and miRNA-181. Methods: The effects of various taurine concentrations (0.25, and 0.75 mg/mL), and LPS (0.1, and 12 mg/mL) on the SH-SY5Y cell line were assessed using the MTT assay. The levels of DHT and DHP were quantified using an ELISA kit. Additionally, the expression levels of miRNA-181 and miRNA-21 genes were examined through Real-Time PCR analysis. Results: The results of the MTT assay showed that treatment with taurine at concentrations of 0.25, and 0.75 mg/mL reduces the toxicity of LPS in SHSY5Y cells. ELISA results indicated that taurine at a concentration of 0.25, and 0.75 mg/mL significantly elevated DHT and DHP hormones in the SH-SY5Y cell line compared to the untreated group (p < 0.01). The expression levels of IL-1β and IL-6 were decreased under the influence of LPS in SH-SY5Y cells after taurine treatment (p < 0.01). Gene expression analysis revealed that increasing taurine concentration resulted in heightened expression of miRNA-181 and miRNA-21, with the most significant increase observed at a concentration of 0.75 mg/mL (p < 0.001). Conclusion: Our study findings revealed that the expression of miRNA-181 and miRNA-21 can be enhanced by taurine. Consequently, exploring the targeting of taurine, miRNA-181, and miRNA-21 or considering hormone therapy may offer potential therapeutic approaches for treating AD or alleviating severe symptoms. Nonetheless, in order to fully comprehend the precise mechanisms involved, additional research is required. [ABSTRACT FROM AUTHOR]

Microbial degradation of fluorinated compounds raised significant attention because of their widespread distribution and potential environmental impacts. Here, we report a bacterial isolate, Rhodococcus sp. NJF-7 capable of defluorinating monofluorinated medium-chain length alkanes. This isolate consumed 2.29 ± 0.13 mmol L− 1 of 1-fluorodecane (FD) during a 52 h incubation period, resulting in a significant release of inorganic fluoride amounting to 2.16 ± 0.03 mmol L− 1. The defluorination process was strongly affected by the initial FD concentration and pH conditions, with lower pH increasing fluoride toxicity to bacterial cells and inhibiting enzymatic defluorination activity. Stoichiometric conversion of FD to fluoride was observed at neutral pH with resting cells, while defluorination was significantly lower at reduced pH (6.5). The discovery of the metabolites decanoic acid and methyl decanoate suggests that the initial attack by monooxygenases may be responsible for the biological defluorination of FD. The findings here provide new insights into microbial defluorination processes, specifically aiding in understanding the environmental fate of organic semi-fluorinated alkane chemicals. [ABSTRACT FROM AUTHOR]

Oxidative dehydrogenation (ODH) of light alkanes to produce C2−C3 olefins is a promising alternative to conventional steam cracking. Perovskite oxides are emerging as efficient catalysts for this process due to their unique properties such as high oxygen storage capacity (OSC), reversible redox behavior, and tunability. Here, we explore AFeO3 (A=Ba, Sr) bulk perovskites for the ODH of ethane and propane under chemical looping conditions (CL‐ODH). The higher OSC and oxygen mobility of SrFeO3 perovskite contributed to its higher activity but lower olefin selectivity than its Ba counterpart. However, SrFeO3 perovskite is superior in terms of cyclic stability over multiple redox cycles. Transformations of the perovskite to reduced phases including brownmillerite A2Fe2O5 were identified by X‐ray diffraction (XRD) as a cause of performance degradation, which was fully reversible upon air regeneration. A pre‐desorption step was utilized to selectively tune the amount of lattice oxygen as a function of temperature and dwell time to enhance olefin selectivity while suppressing CO2 formation from the deep oxidation of propane. Overall, SrFeO3 exhibits promising potential for the CL‐ODH of light alkanes, and optimization through surface and structural modifications may further engineer well‐regulated lattice oxygen for maximizing olefin yield. [ABSTRACT FROM AUTHOR]

Alkanes, single carbon methane to long‐chain hydrocarbons (e.g. hexadecane and tetradecane), are important carbon sources to anaerobic microbial communities. In anoxic environments, archaea are known to utilize and produce methane via the methyl‐coenzyme M reductase enzyme (MCR). Recent explorations of new environments, like deep sea sediments, that have coupled metagenomics and cultivation experiments revealed divergent MCRs, also referred to as alkyl‐coenzyme M reductases (ACRs) in archaea, with similar mechanisms as the C1 utilizing canonical MCR mechanism. These ACR enzymes have been shown to activate other alkanes such as ethane, propane and butane for subsequent degradation. The reversibility of canonical MCRs suggests that these non‐methane‐activating homologues (ACRs) might have similar reversibility, perhaps mediated by undiscovered lineages that produce alkanes under certain conditions. The discovery of these alternative alkane utilization pathways holds significant promise for a breadth of potential biotechnological applications in bioremediation, energy production and climate change mitigation. [ABSTRACT FROM AUTHOR]

Studying the fates of oil components and their interactions with ecological systems is essential for developing comprehensive management strategies and enhancing restoration following oil spill incidents. The potential expansion of Kazakhstan's role in the global oil market necessitates the existence of land-specific studies that contribute to the field of bioremediation. In this study, a set of experiments was designed to assess the growth and biodegradation capacities of eight fungal strains sourced from Kazakhstan soil when exposed to the hydrocarbon substrates from which they were initially isolated. The strains were identified as Aspergillus sp. SBUG-M1743, Penicillium javanicum SBUG-M1744, SBUG-M1770, Trichoderma harzianum SBUG-M1750 and Fusarium oxysporum SBUG-1746, SBUG-M1748, SBUG-M1768 and SBUG-M1769 using the internal transcribed spacer (ITS) region. Furthermore, microscopic and macroscopic evaluations agreed with the sequence-based identification. Aspergillus sp. SBUG-M1743 and P. javanicum SBUG-M1744 displayed remarkable biodegradation capabilities in the presence of tetradecane with up to a 9-fold biomass increase in the static cultures. T. harzianum SBUG-M1750 exhibited poor growth, which was a consequence of its low efficiency of tetradecane degradation. Monocarboxylic acids were the main degradation products by SBUG-M1743, SBUG-M1744, SBUG-M1750, and SBUG-M1770 indicating the monoterminal degradation pathway through β-oxidation, while the additional detection of dicarboxylic acid in SBUG-M1768 and SBUG-M1769 cultures was indicative of the fungus' ability to undertake both monoterminal and diterminal degradation pathways. F. oxysporum SBUG-M1746 and SBUG-M1748 in the presence of cyclohexanone showed a doubling of the biomass with the ability to degrade the substrate almost completely in shake cultures. F. oxysporum SBUG-M1746 was also able to degrade cyclohexane completely and excreted all possible metabolites of the degradation pathway. Understanding the degradation potential of these fungal isolates to different hydrocarbon substrates will help in developing effective bioremediation strategies tailored to local conditions. [ABSTRACT FROM AUTHOR]

Degradation of oil hydrocarbons artificially introduced into bottom sediments in a bioelectrochemical system of a membrane-free (silt) type was studied. Passive bioelectrochemical stimulation by means of electrodes connected by an external circuit with a resistance of 1 kΩ, with an average electric current of ~85 µA was found to cause an increase in degradation during two months from 23.0 to 57.9%. Contamination of bottom sediments with oil (1.32 g/kg) slightly decreased the current in the external circuit of the bioelectrochemical system. The relationship was revealed between the degree of oil degradation and predominant utilization of the lighter n-alkanes in the C14H30–C30H62 series, compared with both the original oil and the residual hydrocarbons of the control. An increase in the representation of the alkB alkane monooxygenase genes relative to the 16S rRNA gene in the total DNA isolated from the sediments was induced by the introduction of hexadecane, both in the case of electrochemical stimulation and in the control. The results may be of interest for the development of new methods of bioelectrochemical removal of organic pollutants from anaerobic environments. [ABSTRACT FROM AUTHOR]

Bio-oils produced through thermochemical conversion processes such as pyrolysis from streamside products obtained from a bio-jet fuel production facility may be used as promising low-carbon alternative feedstocks in the aviation industry. The present investigation applied slow pyrolysis that was conducted at different temperatures to produce bio-oils from hexane-defatted Brassica carinata oilseed meals. The pyrolysis experiments proved that the highest temperature (550℃) produced the maximum bio-oil yield (55.01%), while the lowest temperature (350℃) produced the maximum bio-char (34.93%) and gas (45.84%) yields. An in-depth characterization was performed on the bio-oils to investigate whether they may be employed as alternative feedstocks for bio-jet fuel production. As a result, properties were studied using physicochemical characterization, ultimate analysis, atomic ratios analysis, heating value analysis, inductively coupled plasma-optical emission spectrometry analysis, gas chromatograph-mass spectroscopy, and Fourier-transform infrared spectroscopy. The characterization results of the bio-oils revealed that they had moisture (35.38 − 48.64%), pH (8.50), kinematic viscosity (14.10 − 16.05 cSt), ash content (0.17 − 0.208%), carbon (55.4 − 62.3%), hydrogen (9.02 − 9.29%), nitrogen (6.08 − 6.20%), sulfur (0.61 − 0.69%), oxygen (21.47 − 28.56%), and higher heating value (26.98 − 30.45 MJ/kg). Furthermore, it was found that the major classes of compounds identified include saturated hydrocarbons (13.56 − 14.52%), saturated fatty acids (2.33 − 3.67%), monounsaturated hydrocarbons (30.28 − 34.62%), monounsaturated fatty acids (6.54 − 11.23%), polyunsaturated fatty acids (1.41 − 2.82%), and Others (such as nitrogenated compounds) (38.44 − 39.62%). In conclusion, because of their remarkable excellent characteristics, and because they can be catalytically upgraded into advanced fuels by catalytic hydrotreatment methods (like hydrodeoxygenation and hydrodenitrogenation), and hydrocracking reactions, the oils can be used as promising alternative feedstocks for the aviation industry. [ABSTRACT FROM AUTHOR]

Objectives Little is known about occupational co-exposure. The objective was to assess the prevalence of exposure and co-exposure to biomechanical factors and neurotoxic chemicals in French workers in 2017. Methods Data from the French representative survey SUMER 2017 (SUrveillance Médicale des Expositions aux Risques professionnels) were analyzed. A total of 25 118 workers were included. Exposure to 4 biomechanical factors (manual handling of loads, forceful joint exertion, repetitive movements, and hand-arm transmitted vibrations) and 18 neurotoxic chemicals (n-hexane, perchloroethylene, trichloroethylene, etc.) were assessed using a questionnaire during face-to-face interviews with occupational physicians. Results Among men, 22.9% were exposed to at least one biomechanical factor and 10.2% were exposed to at least one neurotoxic chemical, mainly single exposures. Among women, 10.8% were exposed to at least one biomechanical factor and 3.1% were exposed to at least one neurotoxic chemical, also mainly single exposures. Occupational co-exposure to biomechanical factors and neurotoxic chemicals was observed among 4.8% of men and 0.7% of women. Workers under 30 yr old, blue-collar workers and those working in small companies were more co-exposed than other workers. In men, the prevalence of co-exposure was higher in the construction sector compared to other economic activities. Discussion This study stresses the importance of considering multiple occupational exposures while the current prevention measures are designed to focus on preventing occupational factors individually. [ABSTRACT FROM AUTHOR]

The current paper deals with new metabolites of different groups produced by Azotobacter chroococcum XU1. The strain's metabolic diversity is strongly altered by different factors, and some secondary metabolites are being reported for the first time for this species. As an abiotic/biotic stress response, the strain produced a broad spectrum of indole ring-containing compounds, n-alkanes (eicosane, heneicosane, docosane, tetracosane, and hexacosane), alkanes (7-hexyl eicosane and 2-methyloctacosane), saturated fatty acids (hexanoic and octanoic acids), esters (hexadecanoic acid methyl and pentadecanoic acid-14-methyl-methyl esters), and amides (9-Octadecenamide, (Z)- and 13-Docosenamide, (Z)-). Furthermore, to mitigate the abiotic stress the strain actively produced exopolysaccharide (EPS) to biosorb the Na+ ions. Apart from these metabolites, A. chroococcum XU1 synthesized lactones, namely 1,5-d-gluconolactone and d, l-mevalonic acid lactone in response to carbon source modification. [ABSTRACT FROM AUTHOR]

The oil pipeline transportation of highly waxy oils when it is cold is accompanied by the deposition of paraffins in the inner surface of the pipeline. This study of the initial properties of the oil; the composition, structure, and nature of the components of normal alkanes in oil; and their influence on the aggregative stability of the resulting system makes it possible to find the best solutions to optimize the conditions of oil transportation with the lowest energy costs. This study shows that, according to the content of solid paraffin (14.0–16.2%), the oils of the Kumkol group of fields in Kazakhstan are highly waxy. They are characterized by high yield loss temperature values (+9–+12 °C), which also correlate with the values of the rheological parameters (τ0 1.389 Pa, 3.564 Pa). The influence of the temperature and shear rate on the shear stress and effective viscosity of the initial oils was studied. At temperatures below 20 °C, depending on the shear rate, there is an increase in the effective viscosity values (0.020 Pa∙s, 0.351 Pa∙s). The influence of the nature of solid hydrocarbons on the parameters of the paraffinization process and of the intensity of the paraffinization of the metal surfaces was studied. Our study shows that the main share of n-alkanes in the Kumkol and Akshabulak oils falls on paraffins of the C15–C44 group. The greater the temperature difference between the oil and the cold steel surface (≤40 °C), the lesser the amount of asphalt–resin–paraffin deposits (ARPDs) that fall out on the surface of the rod, although the content of long-chain paraffins prevails in these ARPDs. At the same time, the consistency of the released asphalt–resin–paraffin deposits (ARPDs) becomes denser, which makes their mechanical removal more difficult. Furthermore, the results of this study of the cooling rate shows that the rapid cooling of oils leads to the formation of a large number of crystallization centers, which leads to an increase in the values of the yield loss temperature and kinematic viscosity of the oils. [ABSTRACT FROM AUTHOR]

Porous Si 3 N 4 ceramics with an interconnected pore structure were prepared by a paraffin emulsified suspension method. The effects of the volume ratio of paraffin to silicon and Y 2 O 3 addition on the structure and properties of porous Si 3 N 4 were studied. Uniform dispersed pores introduced by the emulsified paraffine droplets can be observed in the green samples. With the increase of the volume ratio of paraffin to silicon, the bulk density and the strength of the sample were decreased, and the apparent porosity and Darcy permeability were increased. The formation of α-Si 3 N 4 whiskers could be promoted by the addition of the Y 2 O 3 during the nitriding process, and numerous nano whiskers could be obtained in the pores left by the paraffine droplets with suitable addition of the Y 2 O 3. The porous Si 3 N 4 with interconnected whiskers prepared via the paraffin emulsion method exhibited potential application for hot gas particular matter filtration. [ABSTRACT FROM AUTHOR]

Background: Renal cell carcinoma (RCC) stands as the most prevalent form of urogenital cancer. However, there is currently no universally accepted method for predicting the prognosis of RCC. MiRNA holds great potential as a prognostic biomarker for RCC. Methods: A total of 100 cases with complete paraffin specimens and over 5-year follow-up data meeting the requirements were collected. Utilizing the clinical information and follow-up data of the specimens, an information model was developed. The expression levels of eight microRNAs were identified using RTqPCR. Finally, determine and analyze the clinical application value of these microRNAs as prognostic markers for RCC. Results: Significant differences were observed in the expression of two types of miRNAs (miR-378a-5p, miR-23a-5p) in RCC tissue, and three types of miRNAs (miR-378a-5p, miR-642a-5p, miR-23a-5p) were found to be linked to the prognosis of RCC. Establish biomarker combinations of miR-378a-5p, miR-642a-5p, and miR-23a-5p to evaluate RCC prognosis. Conclusion: The combination of three microRNA groups (miR-378a-5p, miR-642a-5p, and miR-23a-5p) identified in paraffin section specimens of RCC in this study holds significant potential as biomarkers for assessing RCC prognosis. [ABSTRACT FROM AUTHOR]

The chemical paraffin removal agent QLJ-1 was developed by analyzing the composition of crude oil, the wax content and the point of paraffin removal in the wellbore of an oilfield in northwest China. The orthogonal test was used to determine the formula as follows: mixed organic solvent (70% aromatics, alkane volume ratio of 2:2:1) + mixed surfactant (7% Tween-80, AEO-9, fatty acid salt mass ratio of 1:2:1) +23% pure water. The results of kinetics and emulsion stability study show that the saturated wax dissolution amount of QLJ-1 is 1.62 g, the wax dissolution rate is 0.0263 g/min, the wax dissolution equilibrium time is about 1h, and the emulsion stability time is 6 d. The wax dissolving effect of QLJ-1 is better than that of the current paraffin remover. The research results of this paper can provide technical support for improving the chemical paraffin removal process in an oilfield in Northwest China. [ABSTRACT FROM AUTHOR]

Soluble di‐iron monooxygenases (SDIMOs) are multi‐component enzymes catalysing the oxidation of various substrates. These enzymes are characterized by high sequence and functional diversity that is still not well understood despite their key role in biotechnological processes including contaminant biodegradation. In this study, we analysed a mutant of Rhodoccocus aetherivorans BCP1 (BCP1‐2.10) characterized by a transposon insertion in the gene smoA encoding the alpha subunit of the plasmid‐located SDIMO SmoABCD. The mutant BCP1‐2.10 showed a reduced capacity to grow on propane, lost the ability to grow on butane, pentane and n‐hexane and was heavily impaired in the capacity to degrade chloroform and trichloroethane. The expression of the additional SDIMO prmABCD in BCP1‐2.10 probably allowed the mutant to partially grow on propane and to degrade it, to some extent, together with the other short‐chain n‐alkanes. The complementation of the mutant, conducted by introducing smoABCD in the genome as a single copy under a constitutive promoter or within a plasmid under a thiostreptone‐inducible promoter, allowed the recovery of the alkanotrophic phenotype as well as the capacity to degrade chlorinated n‐alkanes. The heterologous expression of smoABCD allowed a non‐alkanotrophic Rhodococcus strain to grow on pentane and n‐hexane when the gene cluster was introduced together with the downstream genes encoding alcohol and aldehyde dehydrogenases and a GroEL chaperon. BCP1 smoA gene was shown to belong to the group 6 SDIMOs, which is a rare group of monooxygenases mostly present in Mycobacterium genus and in a few Rhodococcus strains. SmoABCD originally evolved in Mycobacterium and was then acquired by Rhodococcus through horizontal gene transfer events. This work extends the knowledge of the biotechnologically relevant SDIMOs by providing functional and evolutionary insights into a group 6 SDIMO in Rhodococcus and demonstrating its key role in the metabolism of short‐chain alkanes and degradation of chlorinated n‐alkanes. [ABSTRACT FROM AUTHOR]

Two optimization approaches to correct the physical limitations of the Lee–Kesler–Plöcker equation of state for the application to long-chain hydrocarbons are presented. The quality of the approaches is evaluated by comparisons with experimental data and reference equations of state. The calculation of thermodynamic properties for alkanes up to squalane is possible with both approaches, for some of which no highly accurate fundamental equation of state is available in the literature. For the first approach, the original parameter set was refitted with constraints guaranteeing correct behavior of the equation in the liquid state. The densities of long-chain hydrocarbons are reproduced with small deviations, while the results for some short-chain alkanes are worsened. For the second approach, existing Helmholtz energy equations of state are utilized, while keeping the linear interpolation scheme via the acentric factor. Significant improvements are achieved for all fluids considered. [ABSTRACT FROM AUTHOR]

The current study aimed to evaluate Tunisian Tamarix africana Poir biological activities. In this study, novel biological activities of the shoot extracts related to their phenolics investigated. Secondary metabolite contents, antioxidant, anti-inflammatory and cytotoxic activities of four extracts (hexane, dichloromethane, methanol and water) were investigated. Antioxidant activities were assessed via in vitro and ex vivo assays. Besides, anticancer activity was investigated against human lung carcinoma (A-549) and colon adenocarcinoma (DLD-1) cells. The anti-inflammatory ability was evaluated via inhibition of LPS-induced NO production in RAW 264.7 macrophage cell lines. Methanol and water extracts displayed the highest antioxidant (IC50 = 3.3 and 4.3 µg/mL respectively), which are correlated activities correlated with phenolic contents. Hexane extract exhibited an important anti-inflammatory effect inhibiting NO ability by 100% at 80 µg/mL. Besides, T. africana extracts were found to be active against A-549 lung carcinoma cells with IC50 values ranging from 20 to 34 µg/mL. These results suggested that T. africana is considered as a potential source of readily accessible natural molecules with a promising effect on human health and diseases. [ABSTRACT FROM AUTHOR]

With the increase in crude oil transport throughout Canada, the potential for spills into freshwater ecosystems has increased and additional research is needed in these sensitive environments. Large enclosures erected in a lake were used as mesocosms for this controlled experimental dilbit (diluted bitumen) spill under ambient environmental conditions. The microbial response to dilbit, the efficacy of standard remediation protocols on different shoreline types commonly found in Canadian freshwater lakes, including a testing of a shoreline washing agent were all evaluated. We found that the native microbial community did not undergo any significant shifts in composition after exposure to dilbit or the ensuing remediation treatments. Regardless of the treatment, sample type (soil, sediment, or water), or type of associated shoreline, the community remained relatively consistent over a 3-month monitoring period. Following this, metagenomic analysis of polycyclic aromatic and alkane hydrocarbon degradation mechanisms also showed that while many key genes identified in PAH and alkane biodegradation were present, their abundance did not change significantly over the course of the experiment. These results showed that the native microbial community present in a pristine freshwater lake has the prerequisite mechanisms for hydrocarbon degradation in place, and combined with standard remediation practices in use in Canada, has the genetic potential and resilience to potentially undertake bioremediation. [ABSTRACT FROM AUTHOR]