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

Electrocatalytic determination of NADH by means of electrodes modified with MWCNTs and nitroaromatic compounds

Nitro radical anions from megazol and related nitroimidazoles in aprotic media. A father–son type reaction triggered by an acidic proton

Lomefloxacin was reduced on a dropping mercury electrode, producing one or more peaks, depending on the pH of the aqueous medium. Coulometric measurements gave an experimental value of 1 electron for the main peak. Electrolysis was followed by UV spectrophotometry and liquid chromatography (LC), showing that a new band at 413 nm appeared for the electrolysis product in an acidic medium. Furthermore, by using UV spectrophotometry, an apparent pKa value of 6.75 +/- 0.05 was obtained for lomefloxacin corresponding to the carboxyl moiety in the 3-position. For analytical studies, the differential pulse polarographic mode in 0.1 N HCl was selected. The repeatability and reproducibility of the method were adequate (coefficient of variation [CV], 0.51%). The calibration curve method was used for the lomefloxacin concentration range of 7.0 x 10(-6) to 7.0 x 10(-5)M. The detection and quantitation limits were 1.0 x 10(-6) and 6.9 x 10(-6)M, respectively. For purposes of comparison, both UV spectrophotometric and LC (with UV and fluorimetric detection) methods were developed. The polarographic method showed good selectivity with respect to both excipients and degradation products. The recovery study showed a CV of <2% and an average recovery of 99.5% and it was not necessary to treat the sample before analysis. The method was applied to the determination of the uniformity content of lomefloxacin commercial tablets. The polarographic method was also successfully applied to the quantitation of lomefloxacin in urine, and the renal excretion profile was also determined.

Voltammetric behavior and analytical applications of lomefloxacin, an antibacterial fluorquinolone.

The electrochemical behavior of iodo nitroimidazole derivatives such as 1-methyl-4-iodo-5-nitroimidazole (M-I-NIm) and 1-methyl-2,4-diiodo-5-nitroimidazole (M-I2-NIm) and the parent compound 1-methyl-5-nitroimidazole (M-NIm), was studied in protic, mixed and non-aqueous media. The electrochemical study was carried out using Differential Pulse Polarography (DPP), Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and coulometry and as working electrodes mercury and glassy carbon were used. As can be expected, in all media, the effect of introduce iodo as substituent in the nitroimidazole ring produced a decrease of the energy requirements of the nitro group reduction. Certainly, this fact can be explained by the electron withdrawing character of the iodo substituent that acts diminishing the electronic density on the nitro group thus facilitating their reduction. In all the studied media the reduction of M-NIm produced a detectable signal for a nitro radical anion derivative. In the case of M-I-NIm the nitro radical anion was only detectable in both mixed and non-aqueous media. On the other hand the nitro radical anion for the M-I2-NIm was detected only in non-aqueous medium. When glassy carbon electrode was used as the working electrode in a mixed medium a detectable nitro radical anion derivative appeared for all compounds, thus permitting an adequate comparison between them. The obtained values of k2 for M-NIm, M-I-NIm and M-I2-NIm in non-aqueous medium were 5.81×102, 132×102 and 1100×102 M−1 s−1, respectively. From the obtained k2 and t1/2 values in this medium, it is concluded that there is a direct dependence between the presence of iodo substitution in the nitroimidazole ring with the stability of the nitro radical anion.

Nitroradical anion formation from some iodo-substituted nitroimidazoles

A detailed investigation of the electrochemical reduction of 2-nitroimidazole (2-NIm) in a mixed aqueous medium was carried out by means of cyclic voltammetry (CV) at a mercury electrode. The voltammetric behavior of 2-NIm in 60% dimethylformamide (DMF) (0.1 M tetrabutyl ammonium perchlorate, TBAP)/40% aqueous buffer (0.3 M KCl + 0.015 M citric acid + 0.03 M boric acid) is pH-dependent, changing from one irreversible reduction peak at acid pHs to two reduction peaks at alkaline pHs. At pH 2.5 it is possible to obtain a voltammetric pK which is due to the protonation-deprotonation equilibrium produced by the hydroxylamine derivative formed from the reduction of 2-NIm. This indicates that 2-NIm is reduced to the unprotonated hydroxylamine derivative above pH 2.5 and to its protonated form below it. At pH > 7 it is possible to observe a cyclic voltammetric couple due to the one-electron reduction of 2-NIm to produce the corresponding nitro radical anion. Furthermore, the nitro radical anion disproportionates with a rate constant, k 2 , of 6.78 X 10 5 M s -1 and a half-life, t 1/2 , of 1.5 ms for the first half-life. The voltammetric behavior of 2-NIm in aqueous mixed medium is substantially different from that described in nonaqueous medium; in fact, only in the aqueous medium is it possible to study in isolation the nitro radical anion.

Juan A. Squella

Papers

Electrocatalytic determination of NADH by means of electrodes modified with MWCNTs and nitroaromatic compounds

Nitro radical anions from megazol and related nitroimidazoles in aprotic media. A father–son type reaction triggered by an acidic proton

Voltammetric behavior and analytical applications of lomefloxacin, an antibacterial fluorquinolone.

Nitroradical anion formation from some iodo-substituted nitroimidazoles

Electrochemical Reduction of 2-Nitroimidazole in Aqueous Mixed Medium