Evidence for direct molecular oxygen production in CO2 photodissociation

molecular and physiological characterizations of floral scent production in rosa damascena mill.

گل محمدی (r. damascena mill.)مهمترین گونه ای است که در تولید گلاب، عطر و اسانس، در صنعت عطرسازی و دارویی کاربرد دارد. با وجود اهمیت عطر گل محمدی، پژوهش های مولکولی و بیوشیمیایی عطر گل این گونه هنوز در مراحل ابتدایی است. در این پژوهش، ویژگی های مولکولی و فیزیولوژیکی تولید عطر در گل محمدی در آزمایش های مختلف مورد بررسی قرار گرفتند. در آزمایش اول، پژوهشی به منظور بررسی تنوع شیمیایی اسانس میان 44 ت...

Dynamic molecular oxygen production in cometary comae

Abundant molecular oxygen was discovered in the coma of comet 67P/Churyumov-Gerasimenko. Its origin was ascribed to primordial gaseous O2 incorporated into the nucleus during the comet's formation. This thesis was put forward after discounting several O2 production mechanisms in comets, including photolysis and radiolysis of water, solar wind-surface interactions and gas-phase collisions. Here ...

Singlet molecular oxygen by direct excitation.

Direct excitation at 1064 nm and detection of singlet molecular oxygen at 1270 nm is made possible by the availability of powerful YAG-lasers and sensitive NIR photomultipliers. Singlet oxygen was generated in condensed phase at 77 K by direct excitation at 1064 nm (without the use of sensitizers). Several luminescing species were observed by time resolved luminescence spectroscopy and luminesc...

Evidence for direct control of coronary vascular tone by oxygen.

Direct evidence of singlet molecular oxygen generation from peroxynitrate, a decomposition product of peroxynitrite.

The decomposition of peroxynitrite to nitrite and dioxygen at neutral pH follows complex kinetics, compared to its isomerization to nitrate at low pH. Decomposition may involve radicals or proceed by way of the classical peracid decomposition mechanism. Peroxynitrite (ONOOH/ONOO(-)) decomposition has been proposed to involve formation of peroxynitrate (O(2)NOOH/O(2)NOO(-)) at neutral pH (D. Gup...