Humoral and cellular response to BoHV-1 in buffalo and cattle treated with an inactivated marker vaccine

The study is aimed at assessing and comparing the immune response to BoHV-1 elicited by an inactivated marker vaccine in buffaloes and cattle. Vaccination did not produced any local or general reactions in buffaloes. Seroneutralizing antibodies and cellular response by IFN-γ- test have been detected in buffaloes and cattle after a prime/ booster vaccination strategy. Humoral and cellular responses were significantly higher in cattle than in buffaloes. Data pointed out the possibility to use the marker vaccine in buffaloes. However, further studies must be planned to assess the immune pressure of marker vaccines in terms of IBR eradicative attitude in infected buffalo herds

Simulation of Auger decay dynamics in the hard X-ray regime: HCl as a showcase

Auger decay after photoexcitation or photoemission of an electron from a deep inner shell in the hard X-ray regime can be rather complex, implying a multitude of phenomena such as multiple-step cascades, post-collision interaction (PCI), and electronic state-lifetime interference. Furthermore, in a molecule nuclear motion can also be triggered. Here we discuss a comprehensive theoretical method which allows us to analyze in great detail Auger spectra measured around an inner-shell ionization threshold. HCl photoexcited or photoionized around the deep Cl 1s threshold is chosen as a showcase. Our method allows calculating Auger cross sections considering the nature of the ground, intermediate and final states (bound or dissociative), and the evolution of the relaxation process, including both electron and nuclear dynamics. In particular, we show that we can understand and reproduce a so-called experimental 2D-map, consisting of a series of resonant Auger spectra measured at different photon energies, therefore obtaining a detailed picture of all above-mentioned dynamical phenomena at once

Postcollision interaction effects in KLL Auger spectra following argon 1s photoionization

Postcollision interaction effects on the Auger decay of a deep core hole are studied both experimentally and theoretically. KL2,3L2,3 decay spectra of the Ar 1s vacancy are measured with high-energy resolution with excess photon energies ranging from 0 to 200 eV above the ionization threshold. Interaction of the Auger electron with the photoelectron and the ion field manifests itself in the Auger spectra as a distortion of the energy distribution of the Auger electron close to threshold. Moreover, recapture of the photoelectron due to energy exchange is dominating in the low-photon-energy range above threshold. The experimental results are compared with calculations based on the semiclassical approach to the postcollision interaction. The energies of the discrete levels and individual recapture cross sections are computed in the Hartree-Fock approximation. Good agreement is found between the calculated and experimental spectra, validating the model used

Design of TiO2-Surfactin Hybrid Systems with Multifunctional Properties

In recent years, multifunctional inorganic-organic hybrid materials have been widely investigated in order to determine their potential synergetic, antagonist, or independent effects in terms of reactivity. The aim of this study was to design and characterize a new hybrid material by coupling well-known photocatalytic TiO2 nanoparticles with sodium surfactin (SS), a biosurfactant showing high binding affinity for metal cations as well as the ability to interact with and disrupt microorganisms' cell membranes. We used both chemical and colloidal synthesis methodologies and investigated how different TiO2:SS weight ratios affected colloidal, physicochemical, and functional properties. We discovered a clear breaking point between TiO2 and SS single-component trends and identified different ranges of applicability by considering different functional properties such as photocatalytic, heavy metal sorption capacity, and antibacterial properties. At low SS contents, the photocatalytic properties of TiO2 are preserved (conversion of organic dye = 99% after 40 min), and the hybrid system can be used in advanced oxidation processes, taking advantage of the additional antimicrobial SS properties. At high SS contents, the TiO2 photoactivity is inhibited, and the hybrid can be usefully exploited as a UV blocker in cosmetics, avoiding undesired oxidative effects (UV adsorption in the range between 300-400 nm). Around the breaking point (TiO2:SS 1:1), the hybrid material preserves the high surface area of TiO2 (specific surface area around 180 m(2)/g) and demonstrates NOx depletion of up to 100% in 80 min, together with improved adhesion of hybrid antibacterial coating. The last design demonstrated the best results for the concurrent removal of inorganic, organic, and biological pollutants in water/soil remediation applications

Ultrafast nuclear dynamics in the doubly-core-ionized water molecule observed via Auger spectroscopy

We present a combined experimental and theoretical study of the Auger-emission spectrum following double core ionization and excitation of gas-phase water molecules with hard-x-ray synchrotron radiation above the O K−2 threshold. We observe an indication of ultrafast proton motion occurring within the 1.5 fs lifetime of the double-core-hole (DCH) states in water. Furthermore, we have identified symmetric and antisymmetric dissociation modes characteristic for particular DCH states. Our results serve as a fundamental reference for state-of-the-art studies of DCH dynamic processes in liquid water both at synchrotron and free-electron-laser facilities

First-Principles Studies of Hydrogenated Si(111)--7×\times7

The relaxed geometries and electronic properties of the hydrogenated phases of the Si(111)-7$\times$7 surface are studied using first-principles molecular dynamics. A monohydride phase, with one H per dangling bond adsorbed on the bare surface is found to be energetically favorable. Another phase where 43 hydrogens saturate the dangling bonds created by the removal of the adatoms from the clean surface is found to be nearly equivalent energetically. Experimental STM and differential reflectance characteristics of the hydrogenated surfaces agree well with the calculated features.Comment: REVTEX manuscript with 3 postscript figures, all included in uu file. Also available at http://www.phy.ohiou.edu/~ulloa/ulloa.htm

Two-to-one Auger decay of a double L vacancy in argon

We have observed L223−M3 Auger decay in argon where a double vacancy is filled by two valence electrons and a single electron is ejected from the atom. A well-resolved spectrum of these two-to-one electron transitions is compared to the result of the second-order perturbation theory and its decay branching ratio is determined

Auger resonant-Raman decay after Xe L-edge photoexcitation

We have investigated resonant Auger decay of xenon following photoexcitation of each of the three L edges under resonant-Raman conditions, which allowed us to characterize several higher Rydberg transitions. Relative intensities for spectator final states reached after L1−, L2−, and L3-edge excitations are studied in detail. Thanks to state-of-the-art experimental arrangements, our results not only reproduce the previously calculated 3d−25d and nd(n>5) state cross sections after L3 excitation, but also allow extracting the 3d−26d spectator state energy position and revealing its resonant behavior, blurred by the insufficient experimental resolution in previous data sets. The 3d−26p and 3d−27p states reached after L1 excitation as well as the 3d−25d and 3d−26d states reached after L2 excitation are also investigated and their relative intensities are reported and compared to ab initio Dirac-Hartree-Fock configuration-interaction calculations. We found the signature of electronic- state-lifetime interference effects between several coherently excited intermediate states, due to large lifetime broadening. Electron recapture processes are also identified above all three photoionization thresholds

Single and multiple excitations in double-core-hole states of free water molecules

We present a combined experimental and theoretical study of the double-core-hole photoelectron spectrum obtained in isolated water molecules irradiated with hard x-rays above the oxygen K−2 threshold. States of the type O K−2V and multiply excited states are created by single-photon absorption and subsequent one-electron emission. A detailed analysis enabled by high experimental resolution reveals dissociative nuclear dynamics in the K−2V pre-edge states. At the binding energies above the K−2 double-ionization potential, a complex spectral pattern is observed and attributed to highly excited states involving multiple shake-up excitation processes with the aid of state-of-the-art theoretical calculations. A strong broadening due to the nuclear motion indicates a highly dissociative nature of these multiply excited states, in agreement with the theoretical analysis

Subfemtosecond Control of Molecular Fragmentation by Hard X-Ray Photons

Tuning hard x-ray excitation energy along Cl 1s→σ∗ resonance in gaseous HCl allows manipulating molecular fragmentation in the course of the induced multistep ultrafast dissociation. The observations are supported by theoretical modeling, which shows a strong interplay between the topology of the potential energy curves, involved in the Auger cascades, and the so-called core-hole clock, which determines the time spent by the system in the very first step. The asymmetric profile of the fragmentation ratios reflects different dynamics of nuclear wave packets dependent on the photon energy