Pyrene, a Test Case for Deep-Ultraviolet Molecular Photophysics

We determined the complete relaxation dynamics of pyrene in ethanol from the second bright state, employing experimental and theoretical broadband heterodyne detected transient grating and two-dimensional photon echo (2DPE) spectroscopy, using pulses with duration of 6 fs and covering a spectral range spanning from 250 to 300 nm. Multiple lifetimes are assigned to conical intersections through a cascade of electronic states, eventually leading to a rapid population of the lowest long-living excited state and subsequent slow vibrational cooling. The lineshapes in the 2DPE spectra indicate that the efficiency of the population transfer depends on the kinetic energy deposited into modes required to reach a sloped conical intersection, which mediates the decay to the lowest electronic state. The presented experimental–theoretical protocol paves the way for studies on deep-ultraviolet-absorbing biochromophores ubiquitous in genomic and proteic systems

STUDY OF SOME INDICES OF KALLIKREIN-KININ SYSTEM AND OF ANGIOTENSIN-CONVERTING ENZYME (KININASE II) IN PLASMA OF RATS ON HEMOPERFUSION WITH NON-ION-EXCHANGE RESIN

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KALLIKREIN-KININ SYSTEM (KKS) AND ANGIOTENSIN CONVERTING ENZYME ACTIVITY (ACE) IN PATIENTS ON PERIODIC HA•MODIALYSIS (PHD) TREATED WITH RECOMBINANT HUMAN ERYTHROPOIETIN (rhEPO)

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Вища математика. Ч.1. Диференціальне числення у прикладах та задачах

Викладено набір теоретичних та практичних тестів з диференціального числення функції однієї та багатьох змінних. Докладні відповіді, вказівки, розв’язання типових завдань та достатня кількість прикладів для самостійної роботи дозволяють використовувати посібник для всіх видів занять

NEW PRODUCT FROM BULGARIAN ROSE

The chemical composition of extract from rosa (Rosa damascena Mill.) by extraction with tetrafluoroethane was analyzed using GC and GC/MS. The main compounds (concentration higher than 3%) of extract were: phenylethyl alcohol (59.08%) and citronellol (12.31%).The chemical composition of extract from rosa (Rosa damascena Mill.) by extraction with tetrafluoroethane was analyzed using GC and GC/MS. The main compounds (concentration higher than 3%) of extract were: phenylethyl alcohol (59.08%) and citronellol (12.31%)

Environment-Driven Coherent Population Transfer Governs the Ultrafast Photophysics of Tryptophan

By combining UV transient absorption spectroscopy with sub-30-fs temporal resolution and CASPT2/MM calculations, we present a complete description of the primary photo-induced processes in solvated tryptophan. Our results shed new light on the role of the solvent in the relaxation dynamics of tryptophan. We unveil two consecutive coherent population transfer events involving the lowest two singlet excited states: a sub-50-fs non-adiabatic La-->Lb transfer through a conical intersection and a subsequent 220 fs reverse Lb-->La transfer due to solvent assisted adiabatic stabilization of the La state. Vibrational fingerprints in the transient absorption spectra provide compelling evidence of a vibronic coherence established between the two excited states from the earliest times after photoexcitation and lasting until the back-transfer to La is complete. The demonstration of response to the environment as a driver of coherent population dynamics among the excited states of tryptophan closes the long debate on its solvent-assisted relaxation mechanisms and extends its application as a local probe of protein dynamics to the ultrafast timescales