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

We have synthesized three nitrocompounds in order to mimic the model structure of some relevant drugs such as nifedipine. nitrendipine, nisoldipine, nimodipine, and related ones, in order to investigate the effect of structural change on its electrochemical and photodegradation properties. We have found that ortho substitution with a nitro group produces a distortion of the coplanar arrangement, thus decreasing the resonance interaction between the nitro group and the aromatic system. A consequence of this fact is the observed cathodic peak potential shift toward negative values in the ortho-substituted isomer. It is observed that the position of the nitro substitution also produced differences in the photostability of the studied compounds. Stability studies of the compounds in buffered solutions (pH 7) stored in room light conditions show that only the ortho derivative was unstable in the time scale of the experiment (2 h). The instability of the ortho derivative may be explained if we consider that in this isomer, the photoexcited state of the nitro group is not stabilized by resonance as a consequence of the loss of coplanarity between the nitro group and the aromatic ring. Using molecular modeling, we have found that the configuration of minimal energy shows torsion angles of 70, 7.5, and 2.2° for ortho- meta- and para-derivatives, respectively, confirming the lost of coplanarity between the nitro group and the aromatic ring in the ortho derivative.

http://repositorio.uchile.cl/bitstream/handle/2250/120541/Calcium%20channel%20STURM,%202001.pdf;sequence=1

Substituent effects on the electrochemistry and photostability of model compounds of calcium channel antagonist drugs

The use of scanning electrochemical microscopy (SECM) cyclic voltammetry (CV) in tip generation/substrate collection mode is proposed as a new alternative for measuring the kinetics of the chemical coupled reactions of the nitro radical anions generated from nitrocompounds. We have applied the theory developed by Bard and co-workers to obtain the homogeneous rate constant for the dimerization of electrogenerated nitro radical anions from PA-824 (a new antituberculosis agent) and metronidazole (MTZ, a well-known bactericidal agent) in dimethylsulfoxide. Using SECM we have obtained k 2.dim values of 2.15 ± 0.73 × 10 4 [M X s] -1 and 332 ± 74[M X s] -1 for PA-824 and MTZ, respectively. For comparative purposes, we have obtained k 2,dim values of 2.58 ± 0.61 X 10 4 [M X s] -1 and 222 ± 38 [M X s] -1 for PA-824 and MTZ, respectively, but using the CV methodology. The agreement between the results obtained from the well-proved CV methodology and the recently developed SECM methodology support the validity of this new approach. Thus, this work reveals the first approach wherein the SECM technique is applied to the study of the nitro radical anion electrogenerated from nitrocompounds of biological significance.

Juan A. Squella

Papers

Substituent effects on the electrochemistry and photostability of model compounds of calcium channel antagonist drugs

Electrogenerated nitro radical anions: A comparative kinetic study using scanning electrochemical microscopy

Synthesis of Some C‐3,4,5‐Substituted 2,6‐Dimethyl‐1,4‐dihydropyridines (4‐DHPs)

Nitro Aryl 1,4-Dihydropyridine Derivatives: Effects on Trypanosoma cruzi

Electrochemical reduction of nitroso compounds: voltammetric, UV–vis and EPR characterization of ortho- and meta-nitrosotoluene derivatives