Publications by authors named "Chatel G"

() is among the world's most problematic invasive plant species with negative ecological, socio-economic and security consequences. Management operations in areas invaded systematically generate a large quantity of plant waste, most often without outlets. Using this plant material could constitute a new alternative treatment for sustainable management.

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Spent coffee grounds are a promising bioresource that naturally contain around 50 wt% moisture which requires, for a valorization, a drying step of high energy and economic costs. However, the natural water in spent coffee grounds could bring new benefits as a co-solvent during the supercritical CO extraction (SC-CO). This work reports the influence and optimization of pressure (115.

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The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway plays a crucial role in mediating cellular responses to cytokines and growth factors. STAT proteins are activated by tyrosine phosphorylation mediated mainly by JAKs. The abnormal activation of STAT signaling pathways is implicated in many human diseases, especially cancer and immune-related conditions.

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Nucleoporin Nup153 is a multifunctional protein and a known binding partner of mitotic checkpoint protein Mad1 (also known as MAD1L1). The functional relevance of their interaction has remained elusive. Here, we have further dissected the interface and functional interplay of Nup153 and Mad1.

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Article Synopsis
  • This article talks about how chemistry can help make our economy better for the environment and society.
  • It suggests that chemists can make a big difference by using green chemistry, simplifying their processes, and using resources more efficiently.
  • It also highlights the need for chemists to work together with others in different fields to create even better solutions.
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This last century, the development of new medicinal molecules represents a real breakthrough in terms of humans and animal life expectancy and quality of life. However, this success is tainted by negative environmental consequences. Indeed, the synthesis of drug candidates requires the use of many chemicals, solvents, and processes that are very hazardous, toxic, energy consuming, expensive, and generates a large amount of waste.

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Article Synopsis
  • Viticultural waste, particularly grape canes, contains valuable compounds like trans-resveratrol and trans-ε-viniferin (Vf).
  • Various innovative extraction methods, including ultrasound-assisted extraction, microwave-assisted extraction, and pressurized solvent extraction, are analyzed for their effectiveness in recovering these compounds.
  • The paper concludes that while unconventional methods may save time compared to traditional ones, more research is necessary to optimize extraction processes and understand their specific parameters.
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A new field where the utilization of mechanochemistry can create new opportunities is materials chemistry, and, more interestingly, the synthesis of novel nanomaterials. Ball-milling procedures and ultrasonic techniques can be regarded as the most important mechanochemical synthetic tools, since they can act as attractive alternatives to the conventional methods. It is also feasible for the utilization of mechanochemical forces to act synergistically with the conventional synthesis (as a pre-treatment step, or simultaneously during the synthesis) in order to improve the synthetic process and/or the material's desired features.

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Oxidation of alcohols plays an important role in industrial chemistry. Novel green techniques, such as sonochemistry, could be economically interesting by improving industrial synthesis yield. In this paper, we studied the selective oxidation of benzyl alcohol as a model of aromatic alcohol compound under various experimental parameters such as substrate concentration, oxidant nature and concentration, catalyst nature and concentration, temperature, pH, reaction duration, and ultrasound frequency.

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The use of high frequency ultrasound (800 kHz) highlights the non-radical character of the cis-cyclooctene epoxidation mediated by HO and HWO. Combination of moderate mixing brought by the ultrasonic irradiation with precise thermoregulation of the double jacketed sonoreactor demonstrates the potential of this technique for studying and optimizing all the reaction parameters. The results not only reveal that the optimized ultrasonic conditions lead to excellent epoxidation outcomes with 96% yield and 98% selectivity but also to higher selectivities toward the epoxidation product compared with silent conditions.

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The irradiation of concentrated feeds of carbohydrates in alcoholic solution by high-frequency ultrasound (550 kHz) induces the formation of alkylpolyglycosides (APGs). This work is distinct from previous reports in that it does not involve any (bio)catalyst or activating agent, it takes place at only 40 °C, thus avoiding degradation of carbohydrates, and it selectively yields APGs with a degree of polymerization in a window of 2-7, an important limitation of the popular Fischer glycosylation. This ultrasound-based technology proved successful with a range of different valuable carbohydrates and alkyl alcohols.

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Based on the analyses of papers from the literature, and especially those published in Ultrasonics Sonochemistry journal, the contribution of sonochemistry to green chemistry area has been discussed here. Important reminders and insights on the good practices and considerations have been made to understand and demonstrate how sonochemistry can continue to efficiently contribute to green chemistry area in the further studies.

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Lignocellulosic biomass represents a natural renewable chemical feedstock that can be used to produce high value-added chemicals and platform molecules. Nowadays, there are extensive studies on a variety of aspects concerning the valorization of lignocellulosic biomass into desirable products. Among the current technologies for biomass conversion some require extreme conditions along with high temperatures and pressures.

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This systematic experimental investigation reveals that high-frequency ultrasound irradiation (550 kHz) induced oxidation of D-glucose to glucuronic acid in excellent yield without assistance of any (bio)catalyst. Oxidation is induced thanks to the in situ production of radical species in water. Experiments show that the dissolved gases play an important role in governing the nature of generated radical species and thus the selectivity for glucuronic acid.

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The heterogeneous oxidation of vanillyl alcohol to vanillin was investigated on new grounds under eco-friendly conditions in the presence of hydrogen peroxide as an oxidant and water as solvent, coupled with low frequency ultrasonic irradiation. The sono-Fenton-like-assisted vanillyl alcohol oxidation was performed with a high-surface area nanostructured spinel cobalt oxide catalyst exhibiting small crystallites size. The catalytic reaction was also carried out under conventional heating conditions for comparison purposes.

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Based on our original knowledge and experience on both polychlorinated biphenyls (PCBs) identification in aquatic ecosystems, and use of ionic liquids (ILs) as solvents and/or co-catalysts in green chemistry, we drawn a dared comparison between these two families. Indeed, PCBs has been used during several decades for their new properties, but are now considered as prevalent and persistent pollutants; some toxic effects on environment or human are still revealed. ILs, often designated as "green solvents" are increasingly used in numerous applications, but few studies reported about their environmental impact are still controversial.

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Ionic liquids (ILs) as reaction media, and sonochemistry (US) as activation method, represent separately unconventional approaches to reaction chemistry that, in many cases, generate improvements in yield, rate and selectivity compared to traditional chemistry, or even induce a change in the mechanisms or expected products. Recently, these two technologies have been combined in a range of different applications, demonstrating very significant and occasionally surprising synergetic effects. In this book chapter, the advantages and limitations of the IL/US combination in different chemical applications are critically reviewed in order to understand how, and in which respects, it could become an essential tool of sustainable chemistry in the future.

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Chromosomal translocations involving the nucleoporin NUP98 have been described in several hematopoietic malignancies, in particular acute myeloid leukemia (AML). In the resulting chimeric proteins, Nup98's N-terminal region is fused to the C-terminal region of about 30 different partners, including homeodomain (HD) transcription factors. While transcriptional targets of distinct Nup98 chimeras related to immortalization are relatively well described, little is known about other potential cellular effects of these fusion proteins.

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Structural and surface properties of different natural aluminosilicates (layered, chain and framework structural types) exposed of 20 kHz ultrasound irradiation (0-120 min) in aqueous and 35 wt%. aqueous H2O2 dispersions were studied by X-ray diffraction (XRD), dynamic light scattering (DLS), nitrogen adsorption-desorption, thermal analysis, and Fourier transform infrared spectroscopy (FTIR) techniques. It was confirmed that sonication caused slight changes in the structure of investigated minerals whereas their textural properties were significantly affected.

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Liquid multi-ion systems made by combining two or more salts can exhibit charge ordering and interactions not found in the parent salts, leading to new sets of properties. This is investigated herein by examining a liquid comprised of a single cation, 1-ethyl-3-methylimidazolium ([C2mim](+)), and two anions with different properties, acetate ([OAc](-)) and bis(trifluoromethylsulfonyl)imide ([NTf2](-)). NMR and IR spectroscopy indicate that the electrostatic interactions are quite different from those in either [C2mim][OAc] or [C2mim][NTf2].

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Nuclear pore complexes (NPCs) span the 2 membranes of the nuclear envelope (NE) and facilitate nucleocytoplasmic exchange of macromolecules. NPCs have a roughly tripartite structural organization with the so-called nuclear basket emanating from the NPC scaffold into the nucleoplasm. The nuclear basket is composed of the 3 nucleoporins Nup153, Nup50, and Tpr, but their specific role for the structural organization of this NPC substructure is, however, not well established.

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Ionic liquids, as reaction media, and sonochemistry are two recently developing fields of chemistry that present some similarities. Firstly, they constitute separately unconventional approaches to reaction chemistry that, in many cases, generate improvements in yield, rate and selectivity compared to classical chemistry, or even change the mechanisms or products expected. In addition, both are often associated with green chemistry concepts as a result of their properties and their possible eco-friendly uses.

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Article Synopsis
  • * Right now, ultrasound is mainly used for making simple chemicals like biodiesel and for preparing materials, not for creating more valuable substances.
  • * The Review aims to explore why ultrasound isn’t used much for making high-value chemicals yet and suggests ways it could be used more effectively in the future.
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