NO Molecule (no + molecule)

Distribution by Scientific Domains

Selected Abstracts

Nitric oxide and pain: ,Something old, something new'

Challenges have emerged following the revival of nitric oxide (NO) from ,something old', a simple gas derived from nitrogen and oxygen with a role in the early stages of evolution, into ,something new', an endogenously formed biological mediator regulating a wide variety of physiological functions. Although pain is a common sensation, it encompasses multiple neurobiologic components, of which NO is only one. In pain research, the study of NO is complicated by convoluted problems related mostly to the effects of NO, which are pro- or anti-nociceptive depending on the circumstances. This dual function reflects the multi-faceted roles of the NO molecule described in physiology. This review covers current information about NO and its implications in pain mechanisms. In addition, it follows the pain pathways, demonstrating the role of NO in peripheral nociceptive transmission as well in central sensitization. This knowledge may provide the scientific basis for developing new drugs that are indicated for different types of pain, drugs that may be related to the chemical links of NO. A comprehensive approach to understanding the effects of NO will help clinicians identify novel agents that combine the pharmacological profile of native drugs with a controllable manner of NO release. Inhibitors of NO synthesis may have analgesic effects and would be of interest for treating inflammatory and neuropathic pain. Unfortunately, only a few of these compounds have reached the stage of clinical pain trials. [source]

X-ray structure of the NO-bound CuB in bovine cytochrome c oxidase

Kazuhiro Ohta
The X-ray crystallographic structure of nitric oxide-treated bovine heart cytochrome c oxidase (CcO) in the fully reduced state has been determined at 50,K under light illumination. In this structure, nitric oxide (NO) is bound to the CcO oxygen-reduction site, which consists of haem and a Cu atom (the haem a3,CuB site). Electron density for the NO molecule was observed close to CuB. The refined structure indicates that NO is bound to CuB in a side-on manner. [source]

Reduction of Nitric Oxide over Rutile-supported Cu Surfaces: A Quantum Chemical Study

Kai Tan
Abstract The adsorption and decomposition of NO on the stoichiometric rutile-supported Cu surfaces have been studied by means of density functional calculations with an embedded cluster model. The calculation results indicate that NO is favorably adsorbed as O-down and could easily attach another NO molecule to form N2O intermediate or directly be dissociated into N2 and O2. On the basis of the calculated energetics, possible mechanism of NO decomposition reaction has been proposed. [source]

Interaction of CO and NO with the spinel CuCr2O4 (100) surface: A DFT study

Xiang-Lan Xu
Abstract The characteristics of CO and NO molecules at Cu2+ and Cr3+ ion sites on the CuCr2O4 (100) surface have been studied by first principles calculations based on spin-polarized density functional theory (DFT). The calculated results show that adsorption energies for X-down(C, N) adsorption vary in the order: Cu2+ -CO>Cr3+ -NO,Cr3+ -CO>Cu2+ -NO. CO molecules are preferentially adsorbed at Cu sites, whereas NO molecules adsorb favorably at Cu2+ and Cr3+ ion sites. The C-O and N-O stretching frequencies are red-shifted upon adsorption. Combining the analysis of frontier molecular orbitals and Mulliken charge, for CO and NO X-down adsorption systems, the 5, orbitals donate electrons and the 2,* orbitals obtain back-donated electrons. Although for NO with O-down adsorption systems, the NO-2,* orbitals obtain back-donated electrons from substrates without 5,-donation. Coadsorption calculations show the CO/NO mixture adsorb selectively at the Cu2+ion site but simultaneously at the Cr3+ ion site, respectively. 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [source]

Temperature-Programmed Oxidation of Soot in a Hybrid Catalysis-Plasma System

H. Lin
Abstract Non-thermal plasma (NTP) technology was applied to promote the temperature-programmed oxidation (TPO) of soot over a perovskites type of La0.8K0.2MnO3 catalyst. The O radicals originating from the decomposition of O2, as well as NO dissociation if nitrogen oxide were involved, reduce the ignition temperatures of soot. In NO-O2 -He, for example, the ignition temperature decreased to 240,C from 290,C as the voltage increased from 0,kV to 15,kV. The higher voltage also benefited the adsorption of NO molecules onto the catalyst surface (NOad). As a result, the maximum N2/NO ratio (conversion ratio of NO into N2) rose from 23,% to 53,%. Some of the NO molecules were dissociated into N and O radicals in plasma, and hence, the N2/NO ratio was further enhanced due to the combination of N atoms. In any case, the redox process between NOx and soot proved to be important in soot oxidation. [source]