168 research outputs found
Investigations of Bis-chromophore Systems: Relationship between Spectral Behaviour and Charge Transfer in 2-(3-coumaroyl)-benzopyrylium Perchlorates
The dependence of spectral properties and interfragmental charge transfer (ICT) on excitation, relaxation and excited state deactivation of 2-(3-couÂmaroyl)-benzopyryÂlium perchlorates has been analyzed. It was found that the positions of emission bands and rate constants of radiationless deactivation linearly correlate with ICT upon excited state deactivation, and Stokes’ shifts of fluorescence demonstrate linear dependence on ICT upon structural relaxation in the excited state
Spectral and Basic Properties of Flavones in the Ground and Excited States
Dependence between structures of R-oxyflavones and their spectral and basic properties has been investigated. It was found that pKa of flavones, depending on positions of hydroxy and methoxy groups, increase by 6-8 orders of magnitude upon excitation and reaches 3.7-6.6 units. Due to high pKa* value carbonyl group can serve as a proton acceptor in the excited-state intramolecular proton transfer as far as in the formation of phototautomers of 7- and 4'-hydroxyflavones in protic solvents
Hydrodynamic modeling of deconfinement phase transition in heavy-ion collisions at NICA-FAIR energies
We use (3+1) dimensional ideal hydrodynamics to describe the space-time
evolution of strongly interacting matter created in Au+Au and Pb+Pb collisions.
The model is applied for the domain of bombarding energies 1-160 AGeV which
includes future NICA and FAIR experiments. Two equations of state are used: the
first one corresponding to resonance hadron gas and the second one including
the deconfinement phase transition. The initial state is represented by two
Lorentz-boosted nuclei. Dynamical trajectories of matter in the central box of
the system are analyzed. They can be well represented by a fast shock-wave
compression followed by a relatively slow isentropic expansion. The parameters
of collective flows and hadronic spectra are calculated under assumption of the
isochronous freeze-out. It is shown that the deconfinement phase transition
leads to broadening of proton rapidity distributions, increase of elliptic
flows and formation of the directed antiflow in the central rapidity region.
These effects are most pronounced at bombarding energies around 10 AGeV, when
the system spends the longest time in the mixed phase. From the comparison with
three-fluid calculations we conclude that the transparency effects are not so
important in central collisions at NICA-FAIR energies (below 30 AGeV).Comment: 38 pages, 28 figure
X-ray prerequisites for transverse platypodia
Background. Static deformation of the forefoot is one of the common orthopedic pathologies, most often found in women. X-ray index of the first metatarsocuneiform joint (M1C1) is important during preoperative planning to determine the surgeon volume for surgical treatment of static forefoot deformity.Objective. To determine the radiometric prerequisites for the development of transverse platypodia depending on the structure of the first metatarsopharyngeal joint to improve the results of surgical treatment of patients.Material and Methods. From 2015 to 2017, a retrospective study of X-rays of 236 feet (118 patients) performed in a standard dorsoplant projection at rest and with a functional load was carried out.Results. The analysis of the obtained X-ray patterns revealed a direct dependence between the inclination of the articular surface of the medial sphenoid bone and angles of inclination of the articular surface of the base of the first phalanx of the first finger, the head of the first metatarsal bone (PASA), the intertarsal angle (M1M2) and the deflection angle of the first finger (M1P1).Conclusion. Further study of the dependence of the degree of transverse platypodia to the angle of inclination of the articular surface of the medial sphenoid bone and the use of the angle P1C1 as a prognostic indicator, in our opinion, will improve the quality of preoperative planning of surgical treatment of patients with transverse platypodia to reduce the risk of relapse
MRD detection in multiple myeloma: comparison between MSKCC 10-color single-tube and EuroFlow 8-color 2-tube methods
[EN] In patients with multiple myeloma, obtaining posttreatment minimal residual disease (MRD) negativity is associated with longer progression-free survival and overall survival. Here, we compared the diagnostic performance of a single 10-color tube with that of a EuroFlow 8-color 2-tube panel for MRD testing. Bone marrow samples from 41 multiple myeloma patients were tested in parallel using the 2 approaches. Compared with the sum of the cells from the EuroFlow two 8-color tubes, the Memorial Sloan Kettering Cancer Center (MSKCC) single 10-color tube had a slight reduction in total cell number with a mean ratio of 0.85 (range, 0.57-1.46; P < .05), likely attributable to permeabilization of the cells. Percent of plasma cells showed a high degree of concordance (r2 = 0.97) as did normal plasma cells (r2 = 0.96), consistent with no selective plasma cell loss. Importantly, concordant measurement of residual disease burden was seen with abnormal plasma cells (r2 = 0.97). The overall concordance between the 2 tests was 98%. In 1 case, there was a discrepancy near the limit of detection of both tests in favor of the slightly greater theoretical sensitivity of the EuroFlow 8-color 2-tube panel (analytical sensitivity limit of MSKCC single 10-color tube: 6 cells in 1 million with at least 3 million cell acquisitions; EuroFlow 8-color 2-tube panel: 2 cells in 1 million with the recommended 10 million cell acquisitions)
Experimental and Theoretical Investigation into the Effect of the Electron Velocity Distribution on Chaotic Oscillations in an Electron Beam under Virtual Cathode Formation Conditions
The effect of the electron transverse and longitudinal velocity spread at the
entrance to the interaction space on wide-band chaotic oscillations in intense
multiple-velocity beams is studied theoretically and numerically under the
conditions of formation of a virtual cathode. It is found that an increase in
the electron velocity spread causes chaotization of virtual cathode
oscillations. An insight into physical processes taking place in a virtual
cathode multiple velocity beam is gained by numerical simulation. The
chaotization of the oscillations is shown to be associated with additional
electron structures, which were separated out by constructing charged particle
distribution functions.Comment: 9 pages, 8 figure
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