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The use of CO[sub.2] as a CO surrogate for the carbonylation of olefin has attracted considerable attention due to its abundance, readily availability, nontoxicity, and recyclability. In this work, we describe the synthesis of methyl propionate (MPA), a key intermediate for methyl methacrylate in the commercial Lucite Alpha process, by the ruthenium-catalyzed methoxycarbonylation of ethylene with CO[sub.2] as a carbonyl source. An efficient approach to producing MPA has been developed by adding metal halide promoters and dehydrating agents. Control experiments suggest that the NHC-Ru-hydride may be the real active species formed in situ by the reaction of Ru[sub.3](CO)[sub.12] with ionic liquid (IL). NMR data demonstrate that inorganic salts favor the formation of active species, which is an important issue for their promotion effect. In terms of the strategy to overcome chemical equilibrium by the addition of dehydrating agents and IL participation in the formation of NHC-Ru-hydride active species, a tasked IL containing a siloxyl group was employed to Ru-catalyze the methoxycarbonylation of ethylene, which showed higher catalytic efficiency in comparison to IL without a siloxyl group.

This study investigates the potential application of the (Ammonio)butane-1-sulfonate modified Spirulina (Arthrospira) platensis biomasses in the synthesis of 3-aryl-2-oxazolidinones from CO.sub.2, ethylene oxide, and anilines. High catalytic activity and ease of recovery from the reaction mixture using filtration and several reuse times without significant losses in performance are additional eco-friendly attributes of this catalytic system. The effects of the structure of ionic liquid on the catalytic performance were investigated and the various reaction conditions were optimized. This observation was exploited in the direct and selective chemical fixation of CO.sub.2, affording high degrees of CO.sub.2 capture and conversion.

The gaseous plant hormone ethylene is produced by a fairly simple two-step biosynthesis route. Despite this pathway’s simplicity, recent molecular and genetic studies have revealed that the regulation of ethylene biosynthesis is far more complex and occurs at different layers. Ethylene production is intimately linked with the homeostasis of its general precursor S-adenosyl-L-methionine (SAM), which experiences transcriptional and posttranslational control of its synthesising enzymes(SAM synthetase), as well as the metabolic flux through the adjacent Yang cycle. Ethylene biosynthesis continues from SAM by two dedicated enzymes: 1-aminocyclopropane-1-carboxylic (ACC) synthase (ACS) and ACC oxidase (ACO). Although the transcriptional dynamics of ACS and ACO have been well documented, the first transcription factors that control ACS and ACO expression have only recently been discovered. Both ACS and ACO display a type-specific posttranslational regulation that controls protein stability and activity. The nonproteinogenic amino acid ACC also shows a tight level of control through conjugation and translocation. Different players in ACC conjugation and transport have been identified over the years, however their molecular regulation and biological significance is unclear, yet relevant, as ACC can also signal independently of ethylene. In this review, we bring together historical reports and the latest findings on the complex regulation of the ethylene biosynthesis pathway in plants.

RIN-deficient fruits generated by CRISPR/Cas9 initiated partial ripening at a similar time to wild-type (WT) fruits but only 10% WT levels of carotenoids and ethylene were synthesised. RIN-deficient fruit never ripened completely, even when supplied with exogenous ethylene. The low amount of endogenous ethylene that they did produce was sufficient to enable ripening initiation and this could be suppressed by the ethylene perception inhibitor 1-MCP. The reduced ethylene production by RIN-deficient tomatoes was due to an inability to induce autocatalytic system-2 ethylene synthesis, a characteristic feature of climacteric ripening. Production of volatiles and transcripts of key volatile biosynthetic genes were also greatly reduced in the absence of RIN. In contrast, the initial extent and rates of softening in the absence of RIN were similar to WT fruits, although detailed analysis showed the expression of some cell wall modifying enzymes was delayed and others increased in the absence of RIN.These results support a model where RIN and ethylene, via ERFs, are required for fullexpression of ripening genes. Ethylene initiates ripening of mature green fruit, upregulates. RIN expression and other changes, including system-2 ethylene production. RIN, ethylene andother factors are required for completion of the full fruit ripening program.

• The gaseous plant hormone ethylene induces the ripening of climacteric fruit, including apple (Malus domestica). Another phytohormone, auxin, is known to promote ethylene production in many horticultural crops, but the regulatory mechanism remains unclear. • Here, we found that auxin application induces ethylene production in apple fruit before the stage of commercial harvest, when they are not otherwise capable of ripening naturally. • The expression of MdARF5, a member of the auxin response factor transcription factor (TF) family involved in the auxin signaling pathway, was enhanced by treatment with the synthetic auxin naphthaleneacetic acid (NAA). Further studies revealed that MdARF5 binds to the promoter of MdERF2, encoding a TF in the ethylene signaling pathway, as well as the promoters of two 1-aminocyclopropane-1-carboxylic acid synthase (ACS) genes (MdACS3a and MdACS1) and an ACC oxidase (ACO) gene, MdACO1, all of which encode key steps in ethylene biosynthesis, thereby inducing their expression. We also observed that auxin-induced ethylene production was dependent on the methylation of the MdACS3a promoter. • Our findings reveal that auxin induces ethylene biosynthesis in apple fruit through activation of MdARF5 expression.

Plastics, including poly(ethylene terephthalate) (PET), possess many desirable characteristics and thus are widely used in daily life. However, non-biodegradability, once thought to be an advantage offered by plastics, is causing major environmental problem. Recently, a PET-degrading bacterium, Ideonella sakaiensis , was identified and suggested for possible use in degradation and/or recycling of PET. However, the molecular mechanism of PET degradation is not known. Here we report the crystal structure of I. sakaiensis PETase ( Is PETase) at 1.5 Å resolution. Is PETase has a Ser–His-Asp catalytic triad at its active site and contains an optimal substrate binding site to accommodate four monohydroxyethyl terephthalate (MHET) moieties of PET. Based on structural and site-directed mutagenesis experiments, the detailed process of PET degradation into MHET, terephthalic acid, and ethylene glycol is suggested. Moreover, other PETase candidates potentially having high PET-degrading activities are suggested based on phylogenetic tree analysis of 69 PETase-like proteins. Poly(ethylene terephthalate) (PET) is a widely used plastic and its accumulation in the environment has become global problem. Here the authors report the crystal structure of a Ideonella sakaiensis PET-degrading enzyme and propose a molecular mechanism for PET degradation.

According to review of the literature, the influence of nanoparticle diameter with irregular shapes on viscosity requires further research since there is no relation between particle size and nanofluid stability. In this study, SiO.sub.2/EG-water-based nanofluid samples were prepared, and their viscosities were experimentally determined. SiO.sub.2 nanoparticles had sizes of 7, 15, and 40 nm, and the base fluid was a 50% ethylene glycol and 50% water mixture. Nanofluid samples were prepared using a two-step technique. Viscosity change was measured every 10 °C from 20 to 60 °C. The maximum viscosity values were observed for 7, 15, and 40 nm particles over an entire concentration range. Considering all measurements, the highest viscosity increase was 60.51% for 3% SiO.sub.2 (7 nm) at 60 °C, and the lowest viscosity change was 7.72% for 1% SiO.sub.2 (40 nm) at 40 °C. The most stable sample of the current study was 1% SiO.sub.2 (15 nm), and its Zeta potential was - 35.6 mV. Finally, a new empirical equation that included temperature, particle diameter, and concentration terms is suggested to predict dynamic viscosity, with Radj2 = 0.98. It was also compared with previous correlations.

As a result of analysis of the high-resolution Fourier spectrum, the absolute intensities of absorption lines of the [CH.sub.2] = [CD.sub.2] molecule are measured for the first time. Keywords: ethylene, [CH.sub.2] = [CD.sub.2] molecule, absorption line intensities.

Bi sub(1-x)Nd sub(x)FeO sub(3) (x = 0, 0.05, 0.1, 0.15, 0.2) nanoparticles (about 20-50 nm) calcined at 500 and 600 degree C, respectively, were prepared by an ethylene glycol-based sol-gel. The XRD analysis reveals that the BiFeO sub(3) samples are in single phase, and their crystal structure is varied with the Nd content. Due to the small particle size, the uncompensated spin moments on the surface and the suppression of spin helical ordering structure result in a ferromagnetic phase of the BiFeO sub(3) nanoparticles. The magnetization of the Nd-doped samples calcined at 600 degree C is improved with the increase of Nd content, but for the Nd-doped samples calcined at 500 degree C, it shows an opposite trend, which is ascribed to the interplay of size effect and the ratio of Fe super(2+):Fe super(3+) of samples calcined at different temperatures via XPS analysis. The dielectric properties were measured and analyzed for the samples calcined at 500 and 600 degree C. Moreover, the leakage current value of the Bi sub(1-x)Nd sub(x)FeO sub(3) samples can be modulated by the Nd doping, and it reaches a minimum at the Nd content around 0.1.