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81.
82.
Xiaonan Duan Dr. Stéphane C. Corgié Prof. Daniel J. Aneshansley Prof. Peng Wang Prof. Larry P. Walker Prof. Emmanuel P. Giannelis 《Chemphyschem》2014,15(5):974-980
We report a new family of hierarchical hybrid catalysts comprised of horseradish peroxidase (HRP)–magnetic nanoparticles for advanced oxidation processes and demonstrate their utility in the removal of phenol from water. The immobilized HRP catalyzes the oxidation of phenols in the presence of H2O2, producing free radicals. The phenoxy radicals react with each other in a non‐enzymatic process to form polymers, which can be removed by precipitation with salts or condensation. The hybrid peroxidase catalysts exhibit three times higher activity than free HRP and are able to remove three times more phenol from water compared to free HRP under similar conditions. In addition, the hybrid catalysts reduce substrate inhibition and limit inactivation from reaction products, which are common problems with free or conventionally immobilized enzymes. Reusability is improved when the HRP–magnetic nanoparticle hybrids are supported on micron‐scale magnetic particles, and can be retained with a specially designed magnetically driven reactor. The performance of the hybrid catalysts makes them attractive for several industrial and environmental applications and their development might pave the way for practical applications by eliminating most of the limitations that have prevented the use of free or conventionally immobilized enzymes. 相似文献
83.
Caroline Ferrari Eric Olmos Frédérique Balandras Nguyen Tran Isabelle Chevalot Emmanuel Guedon Annie Marc 《Applied biochemistry and biotechnology》2014,172(2):1004-1017
The extensive use of mesenchymal stem cells (MCS) in tissue engineering and cell therapy increases the necessity to improve their expansion. Among these, porcine MCS are valuable models for tissue engineering and are classically expanded in static T-flasks. In this work, different processes of stirred cultures were evaluated and compared. First, the effect of glucose, glutamine, antioxidant, and growth factors concentrations on porcine MSC expansion were analyzed in a suitable medium by performing kinetic studies. Results showed that a lower glucose concentration (5.5 mM) enabled to increase maximal cell concentration by 40 % compared with a higher one (25 mM), while addition of 2 to 6 mM of glutamine increased maximal cell concentration by more than 25 % compared with no glutamine supplementation. Moreover, supplementation with 1 μM thioctic acid increased maximal cell concentration by 40 % compared with no supplementation. Using this adapted medium, microcarriers cultures were performed and compared with T-flasks expansion. Porcine MSC were shown to be able to proliferate on the five types of microcarriers tested. Moreover, cultures on Cytodex 1, Cytopore 2, and Cultispher G exhibited a MSC growth rate more than 40 % higher compared with expansion in T-flasks, while MSC metabolism was similar. 相似文献
84.
85.
Philippe Savarino Emmanuel Colson Guillaume Caulier Igor Eeckhaut Patrick Flammang Pascal Gerbaux 《Molecules (Basel, Switzerland)》2022,27(2)
Saponins are plant and marine animal specific metabolites that are commonly considered as molecular vectors for chemical defenses against unicellular and pluricellular organisms. Their toxicity is attributed to their membranolytic properties. Modifying the molecular structures of saponins by quantitative and selective chemical reactions is increasingly considered to tune the biological properties of these molecules (i) to prepare congeners with specific activities for biomedical applications and (ii) to afford experimental data related to their structure–activity relationship. In the present study, we focused on the sulfated saponins contained in the viscera of Holothuria scabra, a sea cucumber present in the Indian Ocean and abundantly consumed on the Asian food market. Using mass spectrometry, we first qualitatively and quantitatively assessed the saponin content within the viscera of H. scabra. We detected 26 sulfated saponins presenting 5 different elemental compositions. Microwave activation under alkaline conditions in aqueous solutions was developed and optimized to quantitatively and specifically induce the desulfation of the natural saponins, by a specific loss of H2SO4. By comparing the hemolytic activities of the natural and desulfated extracts, we clearly identified the sulfate function as highly responsible for the saponin toxicity. 相似文献
86.
Nonlinear Dynamics - This paper extends the RGD model originally proposed by Richard et al. (J Sound Vib 305(3):432–456, 2007, https://doi.org/10.1016/j.jsv.2007.04.015) to investigate... 相似文献
87.
88.
Tony Tite Vassilios Myrianthopoulos Emmanuel Mikros Roxane Tenta Tzortzis Nomikos 《Tetrahedron》2010,66(50):9620-9628
A number of new pyrazolo[3,4-c] and [4,3-b]pyridine C-nucleosides, which can be viewed as 4- or 6-deazaformycin analogues were synthesized and examined as potential adenosine deaminase (ADA) inhibitors. The compounds were prepared through the condensation of a suitably substituted, lithiated 2- or 4-methylpyridine with tri-O-benzyl-d-ribonolactone, followed by borohydride reduction of the resulting hemiacetals, intramolecular Mitsunobu cyclisation of the derived diols, formation of the pyrazolopyridine ring system and subsequent removal of the protecting groups. These derivatives were designed on the structural basis provided by docking simulations performed within the enzyme catalytic site, however they demonstrated weak ADA inhibitory activity. Theoretical calculations assisted in the interpretation of the obtained biological data, thus providing guidance for rational structural modifications within this molecular scaffold. 相似文献
89.
Emmanuel Philippe 《Comptes Rendus Mathematique》2011,349(21-22):1183-1186
In this Note we give an explicit formula for the length of the shortest geodesic loop for hyperbolic spheres with three singularities of order greater than 3. 相似文献
90.
Emmanuel K. Ackom Warren E. Mabee John N. Saddler 《Applied biochemistry and biotechnology》2010,162(8):2259-2272
The amount of sawmill residue available in Canada to support the emerging cellulosic ethanol industry was examined. A material
flow analysis technique was employed to determine the amount of sawmill residue that could possibly be available to the ethanol
industry per annum. A combination of two key trends—improved efficiency of lumber recovery and increased uptake of sawmill
residues for self-generation and for wood pellet production—have contributed to a declining trend of sawmill residue availability.
Approximately 2.3 × 106 bone-dry tonnes per year of sawmill residue was estimated to be potentially available to the cellulosic ethanol industry
in Canada, yielding 350 million liters per year of cellulosic ethanol using best practices. An additional 2.7 billion liters
of cellulosic ethanol might be generated from sawmill residue that is currently used for competing wood energy purposes, including
wood pellet generation. Continued competition between bioenergy options will reduce the industrial sustainability of the forest
industry. Recommendations for policy reforms towards improved industrial sustainability practices are provided. 相似文献