Exposure of plants to irradiances far above the light saturation point of photosynthesis, known as highlight stress, induces various responses including light adaptation of the photosynthetic apparatus and chloroplast ultrastructure by formation of sun-type chloroplasts. The latter possess a lower cross section for light absorption (less light-harvesting chlorophyll proteins) and higher rates o...

In previous papers (1-3) we reported the occurrence of a light induced fast reversible absorption decrease around 700 m,u in photosynthetic organisms. The effect was ascribed to the photochemical bleaching of a pigment (P700) present in low concentration followed by a spontaneous regeneration in the dark. Such a mechanism predicts that the average concentration level of P700 is determined by th...

The measurement of carbon isotope discrimination (∆) provides an integrated insight into theresponse of plants to environmental change. To investigate the potential use of ∆ for identifyingshade tolerance in rice, five rice varieties were selected and artificially shaded (53% lightreduction) during the grain-filling period in 2010 and 2011, in Sichuan, China. Shadingtreatment had a significant ...

This review article is the second of the comprehensive series on survey of the microwave photochemical and photocatalytic processes, and is focused specially on the microwave-assisted photochemical applications of the electrodeless discharge lamps (EDLs) in organic synthesis. The concept of microwave organic photochemistry is an important issue in synthetic chemistry and material science, and i...

Photochemical internalisation (PCI) is a technique for improving cellular delivery of certain bioactive agents which are prone to sequestration within endolysosomes. There is a wide range of agents suitable for PCI-based delivery including toxins, oligonucleotides, genes and immunoconjugates which demonstrates the versatility of this technique. The basic mechanism of PCI involves triggering rel...

bacteriorhodopsin (br) is a retinal protein that is a light-driven proton pump and has an important role in photosynthesis in archaebacterium halobacterium salinarum. the br molecule absorbs light and photochemical changes occur in it, and different intermediates will be produced in its photochemical cycle that some of them like p and q intermediates have a long half-life. there have been many ...

Measurements of photosynthesis were made in continuous and flashing light of high intensity, using cells varying in chlorophyll content. The amount of chlorophyll present per molecule of carbon dioxide reduced per single flash of light was found to be about 2480 molecules. The length of time required for one unit in the photosynthetic mechanism to complete the cycle of photochemical and Blackma...

Bacterial cells control resistance to the macrolide antibiotic erythromycin using the MphR(A) repressor protein. Erythromycin binds to MphR(A), causing release of the PmphR promoter, activating expression of the 2'-phosphotransferase Mph(A). We engineered the MphR(A)/promoter system to, in conjunction with a light-activatable derivative of erythromycin, enable photochemical activation of gene e...