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Articles de revues sur le sujet « Ether oxygenation »

Auteur : Grafiati
Publié le 9 mars 2023
Mis à jour le 10 mars 2023

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1

Howell, Bob A., et Yoseph G. Daniel. « The impact of sulfur oxidation level on flame retardancy ». Journal of Fire Sciences 36, no 6 (novembre 2018) : 518–34. http://dx.doi.org/10.1177/0734904118806155.

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Compounds containing sulfur in various forms may be used as flame retardants or as adjuvants to promote the activity of other flame-retarding elements, most notably phosphorus. To gain a better understanding of the nature of the sulfur moiety in a flame retardant on performance, a series of phosphorus esters derived from isosorbide containing sulfur at various levels of oxygenation (sulfide, sulfoxide, sulfone) have been prepared and evaluated for flame-retardant impact in diglycidyl ether of bis-phenol A epoxy. In all cases, the presence of sulfur positively impacts flame retardancy. In general, the impact on flame retardancy increases as the level of oxygenation at sulfur increases (sulfone > sulfoxide > sulfide).
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Sundaram, Rajyashree M., Takeo Yamada, Ken Kokubo, Kenji Hata et Atsuko Sekiguchi. « Commercial Wet-Spun Singlewall and Dry-Spun Multiwall Carbon Nanotube Fiber Surface O-Functionalization by Ozone Treatment ». Journal of Nanoscience and Nanotechnology 21, no 12 (1 décembre 2021) : 6151–59. http://dx.doi.org/10.1166/jnn.2021.19536.

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In this work, we demonstrate controlled introduction of O-functional groups on commercial carbon nanotube fibers (CNTFs) with different nanotube morphologies obtained by dry- and wet-spinning by treatment with gaseous ozone (O3(g)). Our test samples were (1) wet-spun fibers of smalldiameter (1–2 nm) singlewall (SW)-CNTs and (2) dry-spun fibers containing large-diameter (20 nm) multiwall (MW)-CNTs. Our results indicate that SW-CNTFs undergo oxygenation to a higher extent than MW-CNTFs due to the higher reactivity of SW-CNTs with a larger curvature strain. Oxygenation resulting from O3 exposure was evidenced as increase in surface O atomic% (at% by X-ray photoelectron spectroscopy, XPS) and as reductions in G/D (by Raman spectroscopy) as well as electrical conductivities due to changes in nanotube graphitic structure. By XPS, we identified the emergence of various types of O-functionalities on the fiber surfaces. After long duration O3 exposure (>300 s for SW-CNTFs and >600 s for MW-CNTFs), both sp2 C═O (carbonyl) and sp3 C–O moieties (ether/hydroxy) were observed on fiber surfaces. Whereas, only sp3 C–O (ether/hydroxy) components were observed after shorter exposure times. O3 treatment led to only changes in surface chemistry, while the fiber morphology, microstructure and dimensions remained unaltered. We believe the surface chemistry controllability demonstrated here on commercial fibers spun by different methods containing nanotubes of different structures is of significance in aiding the practical application development of CNTFs.
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Aly, Hamdy A. H., Nguyen B. Huu, Victor Wray, Howard Junca et Dietmar H. Pieper. « Two Angular Dioxygenases Contribute to the Metabolic Versatility of Dibenzofuran-Degrading Rhodococcus sp. Strain HA01 ». Applied and Environmental Microbiology 74, no 12 (25 avril 2008) : 3812–22. http://dx.doi.org/10.1128/aem.00226-08.

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ABSTRACT Rhodococcus sp. strain HA01, isolated through its ability to utilize dibenzofuran (DBF) as the sole carbon and energy source, was also capable, albeit with low activity, of transforming dibenzo-p-dioxin (DD). This strain could also transform 3-chlorodibenzofuran (3CDBF), mainly by angular oxygenation at the ether bond-carrying carbon (the angular position) and an adjacent carbon atom, to 4-chlorosalicylate as the end product. Similarly, 2-chlorodibenzofuran (2CDBF) was transformed to 5-chlorosalicylate. However, lateral oxygenation at the 3,4-positions was also observed and yielded the novel product 2-chloro-3,4-dihydro-3,4-dihydroxydibenzofuran. Two gene clusters encoding enzymes for angular oxygenation (dfdA1A2A3A4 and dbfA1A2) were isolated, and expression of both was observed during growth on DBF. Heterologous expression revealed that both oxygenase systems catalyze angular oxygenation of DBF and DD but exhibited complementary substrate specificity with respect to CDBF transformation. While DfdA1A2A3A4 oxygenase, with high similarity to DfdA1A2A3A4 oxygenase from Terrabacter sp. strain YK3, transforms 3CDBF by angular dioxygenation at a rate of 29% ± 4% that of DBF, 2CDBF was not transformed. In contrast, DbfA1A2 oxygenase, with high similarity to the DbfA1A2 oxygenase from Terrabacter sp. strain DBF63, exhibited complementary activity with angular oxygenase activity against 2CDBF but negligible activity against 3CDBF. Thus, Rhodococcus sp. strain HA01 constitutes the first described example of a bacterial strain where coexpression of two angular dioxygenases was observed. Such complementary activity allows for the efficient transformation of chlorinated DBFs.
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Wu, Wencheng, Yinying Pu, Han Lin, Heliang Yao et Jianlin Shi. « Starvation-Sensitized and Oxygenation-Promoted Tumor Sonodynamic Therapy by a Cascade Enzymatic Approach ». Research 2021 (3 juin 2021) : 1–17. http://dx.doi.org/10.34133/2021/9769867.

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The therapeutic outcomes of noninvasive sonodynamic therapy (SDT) are always compromised by tumor hypoxia, as well as inherent protective mechanisms of tumor. Herein, we report a simple cascade enzymatic approach of the concurrent glucose depletion and intratumoral oxygenation for starvation-sensitized and oxygenation-amplified sonodynamic therapy using a dual enzyme and sonosensitizer-loaded nanomedicine designated as GOD/CAT@ZPF-Lips. In particular, glucose oxidase- (GOD-) catalyzed glycolysis would cut off glucose supply within the tumor, resulting in the production of tumor hydrogen peroxide (H2O2) while causing tumor cells starvation. The generated H2O2 could subsequently be decomposed by catalase (CAT) to generate oxygen, which acts as reactants for the abundant singlet oxygen (1O2) production by loaded sonosensitizer hematoporphyrin monomethyl ether (HMME) upon the US irradiation, performing largely elevated therapeutic outcomes of SDT. In the meantime, the severe energy deprivation enabled by GOD-catalyzed glucose depletion would prevent tumor cells from executing protective mechanisms to defend themselves and make the tumor cells sensitized and succumbed to the cytotoxicity of 1O2. Eventually, GOD/CAT@ZPF-Lips demonstrate the excellent tumoral therapeutic effect of SDT in vivo without significant side effect through the cascade enzymatic starvation and oxygenation, and encouragingly, the tumor xenografts have been found completely eradicated in around 4 days by the intravenous injection of the nanomedicine without reoccurrence for as long as 20 days.
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Zeng, Wei, Jianzhang Li, Zhihua Mao, Zhou Hong et Shengying Qin. « Synthesis, Oxygenation and Catalytic Oxidation Performance of Crown Ether-Containing Schiff Base-Transition Metal Complexes ». Advanced Synthesis & ; Catalysis 346, no 11 (septembre 2004) : 1385–91. http://dx.doi.org/10.1002/adsc.200404094.

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Fan, Mao Yan, Li Fang Zhang, Hong Xiao et Tian Tian Xie. « Preparation and Electrical Properties of Multilayer Zinc Oxide Varistor by Gelcasting ». Advanced Materials Research 852 (janvier 2014) : 285–90. http://dx.doi.org/10.4028/www.scientific.net/amr.852.285.

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Multilayer ZnO varistors were prepared by aqueous gel tape casting with water-soluble acrylamide as binder. 0.8wt% PAA dispersant was found to be the optimum concentration needed to prepare stable slurry. Plasticizer glycerol has a positive effect on the fluidity of the suspension and oxygen anti-polymerizing inhibitor PEG 2000 deteriorated the fluidity. The addition of 15wt. % PEG2000 eliminates the surface exfoliation absolutely due to the oxygenation of ether units. The solid loading of the slurry was about 71wt% compared to the custom acrylic formulation binder 60wt%. The multilayer ZnO varistors prepared by aqueous gel tape casting display comparable good electrical properties to those prepared by water-based tape casting using custom acrylic formulation binder which is attributed to the high solid loading of slurry.
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Leimanis-Laurens, Mara L., Karen Ferguson, Emily Wolfrum, Brian Boville, Dominic Sanfilippo, Todd A. Lydic, Jeremy W. Prokop et Surender Rajasekaran. « Pediatric Multi-Organ Dysfunction Syndrome : Analysis by an Untargeted “Shotgun” Lipidomic Approach Reveals Low-Abundance Plasma Phospholipids and Dynamic Recovery over 8-Day Period, a Single-Center Observational Study ». Nutrients 13, no 3 (27 février 2021) : 774. http://dx.doi.org/10.3390/nu13030774.

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Lipids are molecules involved in metabolism and inflammation. This study investigates the plasma lipidome for markers of severity and nutritional status in critically ill children. Children with multi-organ dysfunction syndrome (MODS) (n = 24) are analyzed at three time-points and cross-referenced to sedation controls (n = 4) for a total of N = 28. Eight of the patients with MODS, needed veno-arterial extracorporeal membrane oxygenation (VA ECMO) support to survive. Blood plasma lipid profiles are quantified by nano-electrospray (nESI), direct infusion high resolution/accurate mass spectrometry (MS), and tandem mass spectrometry (MS/MS), and compared to nutritional profiles and pediatric logistic organ dysfunction (PELOD) scores. Our results show that PELOD scores were not significantly different between MODS and ECMO cases across time-points (p = 0.66). Lipid profiling provides stratification between sedation controls and all MODS patients for total lysophosphatidylserine (lysoPS) (p-value = 0.004), total phosphatidylserine (PS) (p-value = 0.015), and total ether-linked phosphatidylethanolamine (ether-PE) (p-value = 0.03) after adjusting for sex and age. Nutrition intake over time did not correlate with changes in lipid profiles, as measured by caloric and protein intake. Lipid measurement in the intensive care environment shows dynamic changes over an 8-day pediatric intensive care unit (PICU) course, suggesting novel metabolic indicators for defining critically ill children.
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Latté, Klaus Peter, Oliver Kayser, N. Tan, Macki Kaloga et Herbert Kolodziej. « Unusual Coumarin Patterns of Pelargonium Species Forming the Origin of the Traditional Herbal Medicine Umckaloabo ». Zeitschrift für Naturforschung C 55, no 7-8 (1 août 2000) : 528–33. http://dx.doi.org/10.1515/znc-2000-7-809.

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Abstract The coumarin patterns of Pelargonium sidoides DC. and Pelargonium reniforme CURT., forming the origin of the herbal medicine “umckaloabo”, were analysed and compared for therapeutic equivalence. For both species, members of tri- and tetraoxygenated coumarins almost exclusively were present in the respective metabolic pools. However, the roots of P. sidoides and P. reniforme expressed conspicuously distinct coumarin variations, with umckalin, its 7-O-methyl ether, 7-acetoxy-5,6-dimethoxycoumarin, 6,8-dihydroxy-7-methoxycoumarin, 6,8-dihydroxy-5,7-tetramethoxycoumarin, artelin and three unique coumarin sulfates as uncommon metabolites of this class of secondary products of P. sidoides. Furthermore, the highly oxygenated but known coumarins fraxinol, isofraxetin and fraxidin were associated with the new 8-hydroxy-5,6,7-trimethoxycoumarin as representatives of P. reniforme. Of the twelve identified coumarins only the two species shared the ubiquitous scopoletin and the unique 6,7,8-trihydroxycoumarin. From the oxygenation patterns it is evident that the majority of these Pelargonium coumarins match the recently established basic structural requirements for marked antibacterial activity, i.e. the presence of a methoxy function at C-7 and an OH group at either the C-6 or C-8 position. The current data on the coumarin profiles of each Pelargonium species also indicate a previous erroneous identification of the plant material claimed to be P. reniforme. Absence and presence of umckalin and its 7-O-methyl ether defines P. reniforme and P. sidoides, respectively.
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Eke, Joyner, Lillian Banks, M. Abdul Mottaleb, Andrew J. Morris, Olga V. Tsyusko et Isabel C. Escobar. « Dual-Functional Phosphorene Nanocomposite Membranes for the Treatment of Perfluorinated Water : An Investigation of Perfluorooctanoic Acid Removal via Filtration Combined with Ultraviolet Irradiation or Oxygenation ». Membranes 11, no 1 (25 décembre 2020) : 18. http://dx.doi.org/10.3390/membranes11010018.

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Nanomaterials with tunable properties show promise because of their size-dependent electronic structure and controllable physical properties. The purpose of this research was to develop and validate environmentally safe nanomaterial-based approach for treatment of drinking water including removal and degradation of per- and polyfluorinated chemicals (PFAS). PFAS are surfactant chemicals with broad uses that are now recognized as contaminants with a significant risk to human health. They are commonly used in household and industrial products. They are extremely persistent in the environment because they possess both hydrophobic fluorine-saturated carbon chains and hydrophilic functional groups, along with being oleophobic. Traditional drinking water treatment technologies are usually ineffective for the removal of PFAS from contaminated waters, because they are normally present in exiguous concentrations and have unique properties that make them persistent. Therefore, there is a critical need for safe and efficient remediation methods for PFAS, particularly in drinking water. The proposed novel approach has also a potential application for decreasing PFAS background levels in analytical systems. In this study, nanocomposite membranes composed of sulfonated poly ether ether ketone (SPEEK) and two-dimensional phosphorene were fabricated, and they obtained on average 99% rejection of perfluorooctanoic acid (PFOA) alongside with a 99% removal from the PFOA that accumulated on surface of the membrane. The removal of PFOA accumulated on the membrane surface achieved 99% after the membranes were treated with ultraviolet (UV) photolysis and liquid aerobic oxidation.
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10

Mignion, Lionel, Julie Magat, Olivier Schakman, Etienne Marbaix, Bernard Gallez et Bénédicte F. Jordan. « Hexafluorobenzene in comparison with perfluoro-15-crown-5-ether for repeated monitoring of oxygenation using19F MRI in a mouse model ». Magnetic Resonance in Medicine 69, no 1 (22 mars 2012) : 248–54. http://dx.doi.org/10.1002/mrm.24245.

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Vonwiller, Simone C., Jacqueline A. Warner, Simon T. Mann et Richard K. Haynes. « The formation of a peracetal and trioxane from an enol ether with copper(II) triflate and oxygen : Unexpected oxygenation of aldol intermediates ». Tetrahedron Letters 38, no 13 (mars 1997) : 2363–66. http://dx.doi.org/10.1016/s0040-4039(97)00349-3.

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Kim, Y. V., LYu Kudzina, V. P. Zinchenko et Y. V. Evtodienko. « Changes in the transport of mitochondrial Ca2+ during the culture growth cycle of Tetrahymena pyriformis ». Journal of Cell Science 77, no 1 (1 août 1985) : 47–56. http://dx.doi.org/10.1242/jcs.77.1.47.

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The properties of the Ca2+ transport system of mitochondria, isolated in various phases of growth of static cultures of Tetrahymena pyriformis, were studied. A large increase in the endogenous energy-dependent Ca2+ content of mitochondria was observed as cultures of T. pyriformis passed through the exponential and stationary phases of growth (approx. 0.25 and 50 nmol Ca2+ per mg mitochondrial protein, respectively). Simultaneously, the mitochondria dramatically lost their ability to withstand large concentrations of Ca2+ and ADP. However, in the latter case they were able to phosphorylate a large amount of ADP if the strong Ca2+ chelator, ethylene glycol bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, was initially present in the incubation medium. Furthermore, all the changes observed in mitochondria from the stationary phase cells were completely reversed when cell proliferation was re-activated after the lag phase, either by reseeding the stationery cells in fresh growth medium or by oxygenation of the old medium. In aerobic conditions even a small addition of Ca2+ was able to induce rapid release of Ca2+ from mitochondria isolated during the stationary phase of growth. It is suggested that the redistribution of Ca2+ between the mitochondria and the cytoplasm at the onset of the lag phase may serve as the main trigger for the subsequent biochemical and morphological changes observed in T. pyriformis.
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MORI, Takashi, Tomofumi SANTA, Tsunehiko HIGUCHI, Tadahiko MASHINO et Masaaki HIROBE. « Oxygen Activation by Iron(III)-Porphyrin/NaBH4/Me4NOH System as Cytochrome P-450 Model. Oxygenation of Olefin, N-Dealkylation of Tertiary Amine, Oxidation of Sulfide, and Oxidative Cleavage of Ether Bond. » CHEMICAL & ; PHARMACEUTICAL BULLETIN 41, no 2 (1993) : 292–95. http://dx.doi.org/10.1248/cpb.41.292.

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MORI, T., T. SANTA, T. HIGUCHI, T. MASHINO et M. HIROBE. « ChemInform Abstract : Oxygen Activation by Iron(III)-Porphyrin/NaBH4/Me4N×OH System as Cytochrome P-450 Model. Oxygenation of Olefin such as (I), N- Dealkylation of Tertiary Amine, e.g. (III), Oxidation of Sulfide, e.g. (V), and Oxidative Cleavage of Ether ». ChemInform 25, no 6 (19 août 2010) : no. http://dx.doi.org/10.1002/chin.199406082.

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Gonzalez-de-Castro, Angela, Craig M. Robertson et Jianliang Xiao. « Dehydrogenative α-Oxygenation of Ethers with an Iron Catalyst ». Journal of the American Chemical Society 136, no 23 (29 mai 2014) : 8350–60. http://dx.doi.org/10.1021/ja502167h.

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Xu, Xiaohe, Jian Sun, Yuyan Lin, Jingya Cheng, Pingping Li, Yiyan Yan, Qi Shuai et Yuanyuan Xie. « Copper nitrate-catalyzed oxidative coupling of unactivated C(sp3)–H bonds of ethers and alkanes with N-hydroxyphthalimide : synthesis of N-hydroxyimide esters ». Organic & ; Biomolecular Chemistry 15, no 46 (2017) : 9875–79. http://dx.doi.org/10.1039/c7ob02249b.

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Bressan, Mario, Antonino Morvillo et Giorgio Romanello. « Selective oxygenation of aliphatic ethers catalyzed by ruthenium(II) complexes ». Inorganic Chemistry 29, no 16 (août 1990) : 2976–79. http://dx.doi.org/10.1021/ic00341a024.

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Liu, Ming-Shang, Hai-Wu Du et Wei Shu. « Metal-free allylic C–H nitrogenation, oxygenation, and carbonation of alkenes by thianthrenation ». Chemical Science 13, no 4 (2022) : 1003–8. http://dx.doi.org/10.1039/d1sc06577g.

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Diverse functionalizations of allylic C–H bonds of alkenes by thianthrenation have been demonstrated, featuring Z-selectivity to afford multi-alkyl substituted allylic esters, thioesters, ethers, amines, amides and arenes under metal-free conditions.
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Walaszek, Dominika J., Magdalena Jawiczuk, Jakub Durka, Olga Drapała et Dorota Gryko. « α-Photooxygenation of chiral aldehydes with singlet oxygen ». Beilstein Journal of Organic Chemistry 15 (30 août 2019) : 2076–84. http://dx.doi.org/10.3762/bjoc.15.205.

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Organocatalytic α-oxygenation of chiral aldehydes with photochemically generated singlet oxygen allows synthesizing chiral 3-substituted 1,2-diols. Stereochemical results indicate that the reaction in the presence of diarylprolinol silyl ethers is highly diastereoselective and that the configuration of a newly created stereocenter at the α-position depends predominantly on the catalyst structure. The absolute configuration of chiral 1,2-diols has been unambiguously established based on electronic circular dichroism (ECD) and TD-DFT methods.
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Gonzalez-de-Castro, Angela, Craig M. Robertson et Jianliang Xiao. « ChemInform Abstract : Dehydrogenative α-Oxygenation of Ethers with an Iron Catalyst. » ChemInform 46, no 2 (19 décembre 2014) : no. http://dx.doi.org/10.1002/chin.201502085.

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Liu, Jing, Cong Wan, Aili Zheng, Lianyue Wang, Kaiyue Yin, Dandan Liu, Shengde Wang, Lanhui Ren et Shuang Gao. « α-Oxygenation of Benzylic Ethers to Esters Using MnOx-N@C Catalyst ». Chinese Journal of Organic Chemistry 39, no 3 (2019) : 811. http://dx.doi.org/10.6023/cjoc201807011.

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Mori, Atsushi, Manabu Abe et Masatomo Nojima. « Regioselective Oxygenations ofS-TransDienes, Silyl Dienol Ethers (SDEs), by Triphenyl Phosphite Ozonide (TPPO) and Its Mechanistic Study ». Journal of Organic Chemistry 66, no 10 (mai 2001) : 3548–53. http://dx.doi.org/10.1021/jo015562v.

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Goudarzi, Serra, Jeffrey T. Babicz, Omer Kabil, Ruma Banerjee et Edward I. Solomon. « Spectroscopic and Electronic Structure Study of ETHE1 : Elucidating the Factors Influencing Sulfur Oxidation and Oxygenation in Mononuclear Nonheme Iron Enzymes ». Journal of the American Chemical Society 140, no 44 (16 octobre 2018) : 14887–902. http://dx.doi.org/10.1021/jacs.8b09022.

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Ranft, Andreas, Daniel Golkowski, Tobias Kiel, Valentin Riedl, Philipp Kohl, Guido Rohrer, Joachim Pientka et al. « Neural Correlates of Sevoflurane-induced Unconsciousness Identified by Simultaneous Functional Magnetic Resonance Imaging and Electroencephalography ». Anesthesiology 125, no 5 (1 novembre 2016) : 861–72. http://dx.doi.org/10.1097/aln.0000000000001322.

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Abstract Background The neural correlates of anesthetic-induced unconsciousness have yet to be fully elucidated. Sedative and anesthetic states induced by propofol have been studied extensively, consistently revealing a decrease of frontoparietal and thalamocortical connectivity. There is, however, less understanding of the effects of halogenated ethers on functional brain networks. Methods The authors recorded simultaneous resting-state functional magnetic resonance imaging and electroencephalography in 16 artificially ventilated volunteers during sevoflurane anesthesia at burst suppression and 3 and 2 vol% steady-state concentrations for 700 s each to assess functional connectivity changes compared to wakefulness. Electroencephalographic data were analyzed using symbolic transfer entropy (surrogate of information transfer) and permutation entropy (surrogate of cortical information processing). Functional magnetic resonance imaging data were analyzed by an independent component analysis and a region-of-interest–based analysis. Results Electroencephalographic analysis showed a significant reduction of anterior-to-posterior symbolic transfer entropy and global permutation entropy. At 2 vol% sevoflurane concentrations, frontal and thalamic networks identified by independent component analysis showed significantly reduced within-network connectivity. Primary sensory networks did not show a significant change. At burst suppression, all cortical networks showed significantly reduced functional connectivity. Region-of-interest–based thalamic connectivity at 2 vol% was significantly reduced to frontoparietal and posterior cingulate cortices but not to sensory areas. Conclusions Sevoflurane decreased frontal and thalamocortical connectivity. The changes in blood oxygenation level dependent connectivity were consistent with reduced anterior-to-posterior directed connectivity and reduced cortical information processing. These data advance the understanding of sevoflurane-induced unconsciousness and contribute to a neural basis of electroencephalographic measures that hold promise for intraoperative anesthesia monitoring.
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Takai, Toshihiro, Tohru Yamada, Oliver Rhode et Teruaki Mukaiyama. « Oxygenation of Silyl Enol Ethers and Silyl Ketene Acetals with Molecular Oxygen and Aldehyde Catalyzed by Nickel(II) Complex. A Convenient Method for the Preparation of α-Hydroxy Carbonyl Compounds ». Chemistry Letters 20, no 2 (février 1991) : 281–84. http://dx.doi.org/10.1246/cl.1991.281.

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Cornicelli, J. A., et B. K. Trivedi. « 15-Lipoxygenase and Its Inhibition : A Novel Therapeutic Target for Vascular Disease ». Current Pharmaceutical Design 5, no 1 (janvier 1999) : 11–20. http://dx.doi.org/10.2174/1381612805666230109194856.

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The disease process known as atherosclerosis is the leading cause of morbidity and mortality in the Western world. Current therapies have focused on treating the major risk factors identified to date including plasma lipid derangements, hypertension, clotting disorders, and diabetes. However, a significant number of individuals will be diagnosed with this malady in the apparent absence of known risk factors. Recent attention has turned toward treating the disease at the level of the vessel wall. In this review, we assess the relevancy of the oxygenating enzyme I 5-lipoxygenase (15-LO) as a therapeutic target. In vitro studies suggest that this enzyme may be involved in processes that modify native LDL in such a way as to be avidly taken up by tissue macrophages. In support of this contention are reports demonstrating the colocalization of 15-LO with macrophage-rich arterial lesions and epitopes of modified LDL. Investigations using transgenic animals also suggest that the site of 15-LO expression may be an important factor in the development of the disease. The alteration of important cellular fatty acids may also generate intracellular signals that promote a pro-atherogenic phenotype in the absence of measurable changes in bulk lipid peroxidation. A limited number of studies have exa,mined 15-LO inhibitors and those structural determinants necessary for inhibition of the enzyme. These include natural products and synthetic analogs. Structure activity relationships have been defined for a number of compounds including caffeic acid derivatives, propargyl ethers, and catechols. A novel, potent, specific inhibitor of IS-LO that lacks significant antioxidant activity was tested for its ability to inhibit atherosclerotic lesion formation in vivo. This benzothiopyranoindole virtually eliminated lesion formation in two animal models in the absence of significant changes in plasma lipids. Further, it prevented the progression of pre­ established lesions in another study. Collectively, these data provide a strong scientific rationale for exploring the inhibition of 15-LO as a therapeutic strategy.
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TAKAI, T., Y. YAMADA, O. RHODE et T. MUKAIYAMA. « ChemInform Abstract : Oxygenation of Silyl Enol Ethers (I) and Silyl Ketene Acetals (III) with Molecular Oxygen and Aldehyde Catalyzed by Nickel(II) Complex. A Convenient Method for the Preparation of α-Hydroxy Carbonyl Compounds (II), (IV). » ChemInform 23, no 44 (21 août 2010) : no. http://dx.doi.org/10.1002/chin.199244092.

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Hertkorn, N., M. Harir, B. P. Koch, B. Michalke et P. Schmitt-Kopplin. « High-field NMR spectroscopy and FTICR mass spectrometry : powerful discovery tools for the molecular level characterization of marine dissolved organic matter ». Biogeosciences 10, no 3 (8 mars 2013) : 1583–624. http://dx.doi.org/10.5194/bg-10-1583-2013.

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Abstract. High-performance, non-target, high-resolution organic structural spectroscopy was applied to solid phase extracted marine dissolved organic matter (SPE-DOM) isolated from four different depths in the open South Atlantic Ocean off the Angola coast (3° E, 18° S; Angola Basin) and provided molecular level information with extraordinary coverage and resolution. Sampling was performed at depths of 5 m (Angola Current; near-surface photic zone), 48 m (Angola Current; fluorescence maximum), 200 m (still above Antarctic Intermediate Water, AAIW; upper mesopelagic zone) and 5446 m (North Atlantic Deep Water, NADW; abyssopelagic, ~30 m above seafloor) and produced SPE-DOM with near 40% carbon yield and beneficial nuclear magnetic resonance (NMR) relaxation properties, a crucial prerequisite for the acquisition of NMR spectra with excellent resolution. 1H and 13C NMR spectra of all four marine SPE-DOM showed smooth bulk envelopes, reflecting intrinsic averaging from massive signal overlap, with a few percent of visibly resolved signatures and variable abundances for all major chemical environments. The abundance of singly oxygenated aliphatics and acetate derivatives in 1H NMR spectra declined from surface to deep marine SPE-DOM, whereas C-based aliphatics and carboxyl-rich alicyclic molecules (CRAM) increased in abundance. Surface SPE-DOM contained fewer methyl esters than all other samples, likely a consequence of direct exposure to sunlight. Integration of 13C NMR spectra revealed continual increase of carboxylic acids and ketones from surface to depth, reflecting a progressive oxygenation, with concomitant decline of carbohydrate-related substructures. Aliphatic branching increased with depth, whereas the fraction of oxygenated aliphatics declined for methine, methylene and methyl carbon. Lipids in the oldest SPE-DOM at 5446 m showed a larger share of ethyl groups and methylene carbon than observed in the other samples. Two-dimensional NMR spectra showed exceptional resolution and depicted resolved molecular signatures in excess of a certain minimum abundance. Classical methyl groups terminating aliphatic chains represented ~15% of total methyl in all samples investigated. A noticeable fraction of methyl (~2%) was bound to olefinic carbon. Methyl ethers were abundant in surface marine SPE-DOM, and the chemical diversity of carbohydrates was larger than that of freshwater and soil DOM. In all samples, we identified sp2-hybridized carbon chemical environments with discrimination of isolated and conjugated olefins and α,β-unsaturated double bonds. Olefinic proton and carbon atoms were more abundant than aromatic ones; olefinic unsaturation in marine SPE-DOM will be more directly traceable to ultimate biogenic precursors than aromatic unsaturation. The abundance of furan, pyrrol and thiophene derivatives was marginal, whereas benzene derivatives, phenols and six-membered nitrogen heterocycles were prominent; a yet unassigned set of six-membered N-heterocycles with likely more than one single nitrogen occurred in all samples. Various key polycyclic aromatic hydrocarbon substructures suggested the presence of thermogenic organic matter at all water depths. Progressive NMR cross-peak attenuation from surface to deep marine SPE-DOM was particularly strong in COSY NMR spectra and indicated a continual disappearance of biosignatures as well as entropy gain from an ever increased molecular diversity. Nevertheless, a specific near-seafloor SPE-DOM signature of unsaturated molecules recognized in both NMR and Fourier transform ion cyclotron mass spectrometry (FTICR/MS) possibly originated from sediment leaching. The conformity of key NMR and FTICR/MS signatures suggested the presence of a large set of identical molecules throughout the entire ocean column even though the investigated water masses belonged to different oceanic regimes and currents. FTICR/MS showed abundant CHO, CHNO, CHOS and CHNOS molecular series with slightly increasing numbers of mass peaks and average mass from surface to bottom SPE-DOM. The proportion of CHO and CHNO negative ions increased from surface to depth, whereas CHOS and especially CHNOS molecular series markedly declined. While certain rather aliphatic CHOS and CHNOS ions were observed solely in the surface, deep marine SPE-DOM was enriched in unique unsaturated and rather oxygenated CHO and CHNO molecular series. With the exception of abyssopelagic SPE-DOM at 5446 m, which showed a peculiar CHOS chemistry of unsaturated carbon and reduced sulphur (black sulphur), CHO and CHNO molecular series contributed ~87% to total positive electrospray ionization FTICR mass peak integral, with a near constant ratio of CHNO / CHO molecular compositions near 1.13 ± 0.05. In case of all four marine SPE-DOM, remarkably disparate average elemental compositions as determined from either MS and NMR spectra were observed, caused by a pronounced ionization selectivity in electrospray ionization FTICR/MS. The study demonstrates that the exhaustive characterization of complex unknowns in marine DOM will enable a meaningful classification of individual marine biogeosignatures. Future in-depth functional biodiversity studies with a clear understanding of DOM structure and function might eventually lead to a novel, unified perception of biodiversity and biogeochemistry.
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29

Hertkorn, N., M. Harir, B. P. Koch, B. Michalke, P. Grill et P. Schmitt-Kopplin. « High field NMR spectroscopy and FTICR mass spectrometry : powerful discovery tools for the molecular level characterization of marine dissolved organic matter from the South Atlantic Ocean ». Biogeosciences Discussions 9, no 1 (19 janvier 2012) : 745–833. http://dx.doi.org/10.5194/bgd-9-745-2012.

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Abstract. Non target high resolution organic structural spectroscopy of marine dissolved organic matter (DOM) isolated on 27 November 2008 by means of solid phase extraction (SPE) from four different depths in the South Atlantic Ocean off the Angola coast (3.1° E; −17.7° S; Angola basin) provided molecular level information of complex unknowns with unprecedented coverage and resolution. The sampling was intended to represent major characteristic oceanic regimes of general significance: 5 m (FISH; near surface photic zone), 48 m (FMAX; fluorescence maximum), 200 m (upper mesopelagic zone) and 5446 m (30 m above ground). 800 MHz proton (1H) nuclear magnetic resonance (NMR) 1H NMR, spectra were least affected by fast and differential transverse NMR relaxation and produced at first similar looking, rather smooth bulk NMR envelopes reflecting intrinsic averaging from massive signal overlap. Visibly resolved NMR signatures were most abundant in surface DOM but contributed at most a few percent to the total 1H NMR integral and were mainly limited to unsaturated and singly oxygenated carbon chemical environments. The relative abundance and variance of resolved signatures between samples was maximal in the aromatic region; in particular, the aromatic resolved NMR signature of the deep ocean sample at 5446 m was considerably different from that of all other samples. When scaled to equal total NMR integral, 1H NMR spectra of the four marine DOM samples revealed considerable variance in abundance for all major chemical environments across the entire range of chemical shift. Abundance of singly oxygenated CH units and acetate derivatives declined from surface to depth whereas aliphatics and carboxyl-rich alicyclic molecules (CRAM) derived molecules increased in abundance. Surface DOM contained a remarkably lesser abundance of methyl esters than all other marine DOM, likely a consequence of photodegradation from direct exposure to sunlight. All DOM showed similar overall 13C NMR resonance envelopes typical of an intricate mixture of natural organic matter with noticeable peaks of anomerics and C-aromatics carbon whereas oxygenated aromatics and ketones were of too low abundance to result in noticeable humps at the S/N ratio provided. Integration according to major substructure regimes revealed continual increase of carboxylic acids and ketones from surface to deep marine DOM, reflecting a progressive oxygenation of marine DOM, with concomitant decline of carbohydrate-related substructures. Isolation of marine DOM by means of SPE likely discriminated against carbohydrates but produced materials with beneficial NMR relaxation properties: a substantial fraction of dissolved organic molecules present allowed the acquisition of two-dimensional NMR spectra with exceptional resolution. JRES, COSY and HMBC NMR spectra were capable to depict resolved molecular signatures of compounds exceeding a certain minimum abundance. Here, JRES spectra suffered from limited resolution whereas HMBC spectra were constrained because of limited S/N ratio. Hence, COSY NMR spectra appeared best suited to depict organic complexity in marine DOM. The intensity and number of COSY cross peaks was found maximal for sample FMAX and conformed to about 1500 molecules recognizable in variable abundance. Surface DOM (FISH) produced a slightly (~25%) lesser number of cross peaks with remarkable positional accordance to FMAX (~80% conforming COSY cross peaks were found in FISH and FMAX). With increasing water depth, progressive attenuation of COSY cross peaks was caused by fast transverse NMR relaxation of yet unknown origin. However, most of the faint COSY cross peak positions of deep water DOM conformed to those observed in the surface DOM, suggesting the presence of a numerous set of identical molecules throughout the entire ocean column even if the investigated water masses belonged to different oceanic regimes and currents. Aliphatic chemical environments of methylene (CH2) and methyl (CH3) in marine DOM were nicely discriminated in DEPT HSQC NMR spectra. Classical methyl groups terminating aliphatic chains represented only ~15% of total methyl in all marine DOM investigated. Chemical shift anisotropy from carbonyl derivatives (i.e. most likely carboxylic acids) displaced aliphatic methyl 1H NMR resonances up to δH ~1.6 ppm, indicative of alicyclic geometry which furnishes more numerous short range connectivities for any given atom pairs. A noticeable fraction of methyl (~2%) was bound to olefinic carbon. The comparatively large abundance of methyl ethers in surface marine DOM contrasted with DOM of freshwater and soil origin. The chemical diversity of carbohydrates as indicated by H2CO-groups (δC ~ 62 ± 2 ppm) and anomerics (δC ~ 102 ± 7 ppm) exceeded that of freshwater and soil DOM considerably. HSQC NMR spectra were best suited to identify chemical environments of methin carbon (CH) and enabled discrimination of olefinic and aromatic cross peaks (δC > 110 ppm) and those of doubly oxygenated carbon (δC < 110 ppm). The abundance of olefinic protons exceeded that of aromatic protons; comparison of relative HSQC cross peak integrals indicated larger abundance of olefinic carbon than aromatic carbon in all marine DOM as well. A considerable fraction of olefins seemed isolated and likely sterically constrained as judged from small nJHH couplings associated with those olefins. High S/N ratio and fair resolution of TOCSY and HSQC cross peaks enabled unprecedented depiction of sp2-hybridized carbon chemical environments in marine DOM with discrimination of isolated and conjugated olefins as well as α, β-unsaturated double bonds. However, contributions from five-membered heterocycles (furan, pyrrol and thiophene derivatives) even if very unlikely from given elemental C/N and C/S ratios and upfield proton NMR chemical shift (δH < 6.5 ppm) could not yet been ruled out entirely. In addition to classical aromatic DOM, like benzene derivatives and phenols, six-membered nitrogen heterocycles were found prominent contributors to the downfield region of proton chemical shift (δH > 8 ppm). Specifically, a rather confined HSQC cross peak at δH/δC = 8.2/164 ppm indicated a limited set of nitrogen heterocycles with several nitrogen atoms in analogy to RNA derivatives present in all four marine DOM. Appreciable amounts of extended HSQC and TOCSY cross peaks derived from various key polycyclic aromatic hydrocarbon substructures suggested the presence of previously proposed but NMR invisible thermogenic organic matter (TMOC) in marine DOM at all water depths. Eventually, olefinic unsaturation in marine DOM will be more directly traceable to ultimate biogenic precursors than aromatic unsaturation of which a substantial fraction originates from an aged material which from the beginning was subjected to complex and less specific biogeochemical reactions like thermal decomposition. The variance in molecular mass as indicated from Fourier transform ion cyclotron resonance (FTICR) mass spectra was limited and could not satisfactorily explain the observed disparity in NMR transverse relaxation of the four marine DOM samples. Likewise, the presence of metal ions in isolated marine DOM remained near constant or declined from surface to depth for important paramagnetic ions like Mn, Cr, Fe, Co, Ni and Cu. Iron in particular, a strong complexing paramagnetic ion, was found most abundant by a considerable margin in surface (FISH) marine DOM for which well resolved COSY cross peaks were observed. Hence, facile relationships between metal content of isolated DOM (which does not reflect authentic marine DOM metal content) and transverse NMR relaxation were not observed. High field (12 T) negative electrospray ionization FTICR mass spectra showed at first view rather conforming mass spectra for all four DOM samples with abundant CHO, CHNO, CHOS and CHNOS molecular series with slightly increasing numbers of mass peaks from surface to bottom DOM and similar fractions (~50%) of assigned molecular compositions throughout all DOM samples. The average mass increased from surface to bottom DOM by about 10 Dalton. The limited variance of FTICR mass spectra probably resulted from a rather inherent conformity of marine DOM at the mandatory level of intrinsic averaging provided by FTICR mass spectrometry, when many isomers unavoidably project on single nominal mass peaks. In addition, averaging from ion suppression added to the accordance observed. The proportion of CHO and CHNO molecular series increased from surface to depth whereas CHOS and especially CHNOS molecular series markedly declined. The abundance of certain aromatic CHOS compounds declined with water depth. For future studies, COSY NMR spectra appear best suited to assess organic molecular complexity of marine DOM and to define individual DOM molecules of yet unknown structure and function. Non-target organic structural spectroscopy at the level demonstrated here covered nearly all carbon present in marine DOM. The exhaustive characterization of complex unknowns in \\mbox{marine} DOM will reveal a meaningful assessment of individual marine biogeosignatures which carry the holistic memory of the oceanic water masses (Koch et al., 2011).
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30

Liu, Kai-Jian, Zheng Wang, Ling-Hui Lu, Jin-Yang Chen, Fei Zeng, Ying-Wu Lin, Zhong Cao, Xianyong Yu et Wei-Min He. « Synergistic cooperative effect of CF3SO2Na and bis(2-butoxyethyl)ether towards selective oxygenation of sulfides with molecular oxygen under visible-light irradiation ». Green Chemistry, 2021. http://dx.doi.org/10.1039/d0gc02663h.

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A practical method for the switchable synthesis of sulfoxides and sulfones through visible-light-initiated CF3SO2Na/2-butoxyethyl ether synergistic catalyzed oxygenation of sulfides was developed.
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31

Boehm-Sturm, Philipp, Susanne Mueller, Nancy Freitag, Sophia Borowski, Marco Foddis, Stefan P. Koch, Sebastian Temme, Ulrich Flögel et Sandra M. Blois. « Phenotyping placental oxygenation in Lgals1 deficient mice using 19F MRI ». Scientific Reports 11, no 1 (22 janvier 2021). http://dx.doi.org/10.1038/s41598-020-80408-9.

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AbstractPlacental hypoperfusion and hypoxia are key drivers in complications during fetal development such as fetal growth restriction and preeclampsia. In order to study the mechanisms of disease in mouse models, the development of quantitative biomarkers of placental hypoxia is a prerequisite. The goal of this exploratory study was to establish a technique to noninvasively characterize placental partial pressure of oxygen (PO2) in vivo in the Lgals1 (lectin, galactoside-binding, soluble, 1) deficient mouse model of preeclampsia using fluorine magnetic resonance imaging. We hypothesized a decrease in placental oxygenation in knockout mice. Wildtype and knockout animals received fluorescently labeled perfluoro-5-crown-15-ether nanoemulsion i.v. on day E14-15 during pregnancy. Placental PO2 was assessed via calibrated 19F MRI saturation recovery T1 mapping. A gas challenge with varying levels of oxygen in breathing air (30%, 60% and 100% O2) was used to validate that changes in oxygenation can be detected in freely breathing, anesthetized animals. At the end of the experiment, fluorophore-coupled lectin was injected i.v. to label the vasculature for histology. Differences in PO2 between breathing conditions and genotype were statistically analyzed with linear mixed-effects modeling. As expected, a significant increase in PO2 with increasing oxygen in breathing air was found. PO2 in Lgals1 knockout animals was decreased but this effect was only present at 30% oxygen in breathing air, not at 60% and 100%. Histological examinations showed crossing of the perfluorocarbon nanoemulsion to the fetal blood pool but the dominating contribution of 19F MR signal is estimated at > 70% from maternal plasma based on volume fraction measurements of previous studies. These results show for the first time that 19F MRI can characterize oxygenation in mouse models of placental malfunction.
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32

Chaudhuri, Shayantan, Samuel J. Hall, Benedikt P. Klein, Marc Walker, Andrew J. Logsdail, Julie V. Macpherson et Reinhard J. Maurer. « Coexistence of carbonyl and ether groups on oxygen-terminated (110)-oriented diamond surfaces ». Communications Materials 3, no 1 (28 janvier 2022). http://dx.doi.org/10.1038/s43246-022-00228-4.

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AbstractDiamond-based materials have unique properties that are exploited in many electrochemical, optical, thermal, and quantum applications. When grown via chemical vapor deposition (CVD), the growth rate of the (110) face is typically much faster than the other two dominant crystallographic orientations, (111) and (100). As such, achieving sufficiently large-area and high-quality (110)-oriented crystals is challenging and typically requires post-growth processing of the surface. Whilst CVD growth confers hydrogen terminations on the diamond surface, the majority of post-growth processing procedures render the surface oxygen-terminated, which in turn impacts the surface properties of the material. Here, we determine the oxygenation state of the (110) surface using a combination of density functional theory calculations and X-ray photoelectron spectroscopy experiments. We show that in the 0–1000 K temperature range, the phase diagram of the (110) surface is dominated by a highly stable phase of coexisting and adjacent carbonyl and ether groups, while the stability of peroxide groups increases at low temperatures and high pressures. We propose a mechanism for the formation of the hybrid carbonyl-ether phase and rationalize its high stability. We further corroborate our findings by comparing simulated core-level binding energies with experimental X-ray photoelectron spectroscopy data on the highest-quality (110)-oriented diamond crystal surface reported to date.
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33

YONEDA, N., T. KIUCHI, T. FUKUHARA, A. SUZUKI et G. A. OLAH. « ChemInform Abstract : SUPERACID CATALYZED OXYGENATION OF ALIPHATIC ETHERS WITH OZONE ». Chemischer Informationsdienst 16, no 9 (5 mars 1985). http://dx.doi.org/10.1002/chin.198509129.

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34

Mubarak, M. Qadri E., Hafiz Saqib Ali, Jimei Zhou, Chaoqun Li, Jianliang Xiao et Samuel P. de Visser. « Dehydrogenative α‐Oxygenation of Cyclic Ethers by a High‐Valent Manganese(IV)‐Oxo Species ». European Journal of Inorganic Chemistry, 24 novembre 2022. http://dx.doi.org/10.1002/ejic.202200621.

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35

Dautzenberg, Geertje, Mirko Gerhardt et Birgit Kamm. « Bio based fuels and fuel additives from lignocellulose feedstock via the production of levulinic acid and furfural ». Holzforschung 65, no 4 (1 juin 2011). http://dx.doi.org/10.1515/hf.2011.081.

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Abstract The demand for biomass-derived fuels and fuel additives, particularly in the transportation sector, has stimulated intense research efforts in the chemistry of levulinic acid and levulinic acid secondary products over the past decade. Additionally, recent technological progress in lignocellulosic feedstock (LCF) chemistry has also increased attention in this regard. As a result, several oxygenating fuel additives with potential applications in both gasoline and diesel fuels have been identified. Some of the chemicals, such as ethyl valerate, appear to be viable alternatives to the currently used branched, short-chain ethers that are derived from side products of petrol refining. Cost-effective applications of lignocellulosic biomass are a crucial aspect of its feasibility. In consideration of the LCF biorefinery concept, the feasibility must also include the chemical pulping of LCF and the comprehensive utilisation of its main constituents cellulose, hemicelluloses, and lignin. The present study focuses on cellulose and hemicelluloses as viable sources for the production of biofuels and biofuel additives. Multifunctional catalysis, including hydrogenation and acid catalysis are the primary instruments used for the conversion of the monomeric carbohydrate building blocks, i.e., mainly C5 sugars, such as xylose and arabinose, and C6 sugars in the form of glucose and their respective secondary products, furfural and levulinic acid. Lignin utilisation is not addressed in this paper.
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36

Menendez Cepero, Silvia. « OZONE THERAPY : TERATOGENIC STUDY OF OZONE. POSSIBLE INDICATIONS IN OBSTETRICS AND GYNECOLOGY ». Journal of Ozone Therapy 2, no 2 (4 mars 2018). http://dx.doi.org/10.7203/jo3t.2.2.2018.11129.

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Ozone is a powerful oxidant, surpassed, in this regard, only by fluorine. Its doubtless strong reactivity has contributed to establish the dogma that ozone is always toxic and its medical application must be proscribed. However, ozone therapy has been used for therapeutic purposes since the beginning of the last century and its use is increasingly demanded nowadays. For proper enlightenment and guidance of the person interested in the use of ozone for medical purposes, scientific documentation on the safety/toxicity profile of this acclaimed procedure becomes necessary. Taking into account that the National Health Regulatory Agencies require of documentation with scientific trials for sanitary registration of drugs and therapy procedures, different toxicological tests were performed in Cuba using experimental animals, following the guidelines from the Cuban Regulatory Agency, Food Drug Administration, International Standards Organization and the Health World Organization aimed at proving the safety of ozone therapy administration. In this lecture, the teratogenic study of ozone by rectal insufflation (RI) is presented. Female Wistar rats (200-250 g) were divided into 3 experimental groups: 1- control (n=15), without any treatment; 2- treated with 1 mL of ozone (n=17) at a concentration of 34 ?g/mL (150 ?g/kg); 3- treated with 4 mL of ozone (n=17) at a concentration of 90 ?g/mL (1600 ?g/kg). Ozone was administered by RI during 10 sessions, from the 6th to the 15th day of gestation. The pregnancy was confirmed by the presence of spermatozoa in the vaginal exudates. It was considered that the animals with positive exudates were in the 0 day of gestation. In the 19th day of gestation, animals were euthanized by an ether overdose and the fetuses were obtained by cesarean. The number of corpus luteum, implantations, alive and dead fetuses, reabsorptions, as well as the weight and the length cranium-caudal of each fetus were registered. Alive fetuses were examined to find any external malformations. No toxic effect was observed in the pregnant rats subjected to the ozone treatment by RI. Mother weight gain did not show significant differences among the groups, neither the other indicators (number of corpus luteum, implantations, alive and dead fetus, reabsorptions). In respect to the fetus morphology, no external, skeletal or visceral malformations were observed. The weight and the length cranium-causal did not show significant differences among the groups. It is concluded that no teratogenic nor embriotoxic effects were found after the ozone application by rectal insufflation at the doses studied. With respect to the application of ozone therapy in Obstetrics, an update of the papers published about this topic was presented. They referred the use of ozone therapy in: pregnant womens with hypertension, genital or no genital infections during pregnancy, threatened abortion, intrauterine fetal hypoxia, among others. For example, the effect of ozone therapy by rectal insufflation on fetoplacental blood flow in hypertensive pregnant women, with 24 weeks of gestation, indicated a better fetoplacental blood flow, achieving a greater oxygenation in the group treated with ozone plus antihypertensive treatment (methyldopa) in comparison with a control group treated only with the conventional treatment. Also, a reduction of methyldopa in 23.7 % of the initial doses was found in the ozone group as opposed to an increase of 40.8% in the control group. Another study about ozone therapy as the main component of the complex treatment of threatened abortion, using ozonated saline solution in the first (group I) or second semester (group II) showed a decrease in the molecular products of lipid peroxidation and a simultaneous increase in the antioxidant activity. Also, with ozone therapy the pregnancy was preserved and prolonged to the physiological terms of labor in 86% of patients inside group I and in 85% of patients inside group II. However, in the control group (conventional treatment) I and II, it was possible to preserve the pregnancy in 65 and 60% of cases, respectively. In the ozone group, 80% of newborn babies received 7-10 points (maximum value) according to Apgar's score, however, only 58.3% in the control group. In Gynecology, an interesting paper was reviewed about distal fallopian tube recanalization using ozone treatment. In the ozone group, the ozone was introduced in the uterine cavity and in the case of the control group, anti-inflammatory drugs and antibiotics was used. The overall recanalization rate was significantly higher in the ozone group (93%) as compared to the control group (79%) 6-months after intervention (p < 0.01). The re-adhesion rate in the ozone group was significantly lower than the control group (p < 0.01). The pregnancy rate after 12 months of intervention was significantly higher in the ozone group (59%) compared to the control group (43%) (p < 0.05). These results were highly encouraging and hold promise for treating distal tubal obstruction in infertile females. For inflammatory diseases in female genital organs, intravaginal ozone has been used. Ozone restores the body's own defense abilities by the normalization of vaginal mucosa local immunity, prevents the generalization of inflammatory processes, facilitates uterus healing, reduces the treatment time with no complications or side effects. In Cuba we have a vast experience in the use of ozonated sunflower oil in the treatment of vulvovaginitis, human papillomavirus, acuminate condyloma, genitalis herpes virus with very good results. In summary, we can state that preclinical and clinical studies presented here about the application of ozone therapy in Obstetrics and Gynecology, in the different ways of ozone applications, do not demonstrate any adverse effect or complication. However, more controlled clinical trials are necessary to perform in order to prove the inocuity of ozone therapy, mainly in Obstetrics, where threre are still questions to be clarified.
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