Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

and Fuels Changzhi Li,† Xiaochen Zhao,† Aiqin Wang,† George W. Huber,†,‡ and Tao Zhang*,† †State Key Laborotary of Catalysis, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China ‡Department of Chemical and Biological Engineering, University of WisconsinMadison, Madison, Wisconsin 53706, United States

Catalytic Transformation of Lignin for the Production of Chemicals and Fuels

Peroxynitrite--the product of the diffusion-controlled reaction of nitric oxide with superoxide radical--is a short-lived oxidant species that is a potent inducer of cell death Conditions in which the reaction products of peroxynitrite have been detected and in which pharmacological inhibition of its formation or its decomposition have been shown to be of benefit include vascular diseases, ischaemia-reperfusion injury, circulatory shock, inflammation, pain and neurodegeneration In this Review, we first discuss the biochemistry and pathophysiology of peroxynitrite and then focus on pharmacological strategies to attenuate the toxic effects of peroxynitrite These include its catalytic reduction to nitrite and its isomerization to nitrate by metalloporphyrins, which have led to potential candidates for drug development for cardiovascular, inflammatory and neurodegenerative diseases

Peroxynitrite: biochemistry, pathophysiology and development of therapeutics

Cyclodextrins as pharmaceutical solubilizers.

Superoxide ion (O2•–) is of great significance as a radical species implicated in diverse chemical and biological systems. However, the chemistry knowledge of O2•– is rather scarce. In addition, numerous studies on O2•– were conducted within the latter half of the 20th century. Therefore, the current advancement in technology and instrumentation will certainly provide better insights into mechanisms and products of O2•– reactions and thus will result in new findings. This review emphasizes the state-of-the-art research on O2•– so as to enable researchers to venture into future research. It comprises the main characteristics of O2•– followed by generation methods. The reaction types of O2•– are reviewed, and its potential applications including the destruction of hazardous chemicals, synthesis of organic compounds, and many other applications are highlighted. The O2•– environmental chemistry is also discussed. The detection methods of O2•– are categorized and elaborated. Special attention is given to the f...

Superoxide Ion: Generation and Chemical Implications

Here, we reveal a different way of doing the voltammetric experiments that considers the electroactive species packaged in the electrodic phase instead of dissolved in solution. In this way, it is possible to obtain voltammograms of insoluble species. In this work, the method is exemplified by obtaining voltammograms for weakly soluble coumarins but it could be extrapolated to other weakly soluble compounds. We have studied a comprehensive series of 3-acetyl-hydroxycoumarins derivatives which are insoluble in aqueous medium but capable of being trapped in a three-dimensional multi-walled carbon nanotubes (MWCNT) network. Consequently, an electrodic phase composed of an MWCNT modified glassy carbon electrode (GCE) containing the coumarin derivative is prepared. The voltammetric experiment is performed with the above electrodic phase and an aqueous medium as the solution phase. All the coumarin derivatives show one anodic peak due to the oxidation of the hydroxyl group in the phenyl ring. The oxidation peaks follow a one-electron, one-proton irreversible, pH-dependent process for all monohydroxylated compounds. The Ep values are closely dependent of the substituent effect being the 7,8-cum derivative more easily oxidized due to both the electron donor effect of neighboring hydroxyls groups and hydrogen bonding interaction between them. On the other hand, the hydroxyl of the 7-cum derivative is the most difficult to oxidize due to the electron-attracting effect of the lactone carbonyl group at position 2 and acetyl carbonyl at position 3 which is conjugated with OH at 7 positions. From the breaks in the graphs Ep versus pH, we estimate the voltammetric pKa values for all the studied coumarin derivatives.

https://link.springer.com/content/pdf/10.1007%2Fs10008-017-3750-9.pdf

New voltammetric method useful for water insoluble or weakly soluble compounds: application to pKa determination of hydroxyl coumarin derivatives

The electrochemistry of 2,2-dimethyl-(3H)-3-(N-3'-nitrophenylamino)naphtho[1,2- b]furan-4,5-dione ([Q]-PhNO2), on mercury was investigated. The first peak is consistent with a quasi-reversible one-electron reduction of the ortho-quinone, forming [Q•-]-PhNO2, while the second one, bielectronic, corresponds to the simultaneous reduction of the latter radical to a dianion and the nitro group to a nitro radical anion. The second order rate constant, kdisp, for the decay of [Q•-]-PhNO2 is 15.188 x 103 ± 827 mol"1 L s"1 and the t1/2 equals 0.06 s. E17Ic values for [Q]-PhNO2 and its precursor, nor-β-lapachone, are similar. The ease of semiquinone generation and its stability are parameters statistically relevant in the correlation biochemical/theoretical aspects.

/pdf/electrochemical-study-on-mercury-of-a-meta-nitroarylamine-2stlajytbd.pdf

Electrochemical study, on mercury, of a Meta-nitroarylamine derivative of nor-β-lapachone, an antitumor and trypanocidal compound

The electrochemical behavior of three different megazol analogues substituted at position 4 and their comparison with the parent compound megazol in protic and aprotic media by cyclic voltammetry, Tast and differential pulse polarography was studied. All the compounds were electrochemically reducible in both media with the reduction of the nitroimidazole group the main voltammetric signal. The one-electron reduction couple due to the nitro radical anion formation was visualized only in aprotic media for all these compounds. By applying cyclic voltammetric methodology we have calculated the dimerization reaction decay constants (k2) of the corresponding nitro radical anions in aprotic media. The nitro radical anion obtained from the synthesized nitroimidazole compound having a bromine substituent in 4-position (GC-141) was significantly more stable than the corresponding radical formed from the compound lacking of the substituent in 4-position, megazol.

/pdf/electrochemical-study-of-4-substituted-analogues-of-megazol-r5hcgwrxio.pdf

Electrochemical Study of 4‐Substituted Analogues of Megazol

The reductive electrochemistry of 1-methyl-4-nitro-2-hydroxymethylimidazole, a 4-nitroimidazole derivative, was examined in the presence of surfactants anionic as sodium dodecyl sulfate (SDS), nonionic, Triton-X, Cationic, Hyamine and Cetyl Trimethyl Ammonium Bromide (CTAB). The reductive mechanism of the nitroimidazole derivative was found to be dependent of both, nature and concentration of the surfactants.

Micellar effects on the reduction of 4-nitroimidazole derivative: Detection and quantification of the nitroradical anion

Tbis work was partiall)' supported by grants Irom FONDECYT
(91/0881) and DTI Universidad de Chile (Q-3118/9223).

Juan A. Squella

Papers

New voltammetric method useful for water insoluble or weakly soluble compounds: application to pKa determination of hydroxyl coumarin derivatives

Electrochemical study, on mercury, of a Meta-nitroarylamine derivative of nor-β-lapachone, an antitumor and trypanocidal compound

Electrochemical Study of 4‐Substituted Analogues of Megazol

Micellar effects on the reduction of 4-nitroimidazole derivative: Detection and quantification of the nitroradical anion

Nitro radical anion formation from nitro-substituted amphetamine derivatives