Recommended Data on Electron-ion Collision Strengths and Effective Collision Strengths for Fe X. Fe XI and Fe XIII Ions

Data obtained for electron-induced excitation transitions between levels with principal quantum numbers n=3 in Cl-like Fe X, S-like Fe XI, and Si-like Fe XIII ions by different theoretical methods were compared, and recommended data for electron collision strengths and effective collision strengths have been chosen. Simple analytical formulas with 7 free parameters were used to describe electron temperature dependence of effective collision strengths in a wide temperature range. The values of free parameters have been determined by fitting the recommended numerical data. The obtained results can be used for plasma kinetics calculations and for spectroscopic methods of plasma diagnostics

Modification of Coulomb law and energy levels of the hydrogen atom in a superstrong magnetic field

We obtain the following analytical formula which describes the dependence of the electric potential of a point-like charge on the distance away from it in the direction of an external magnetic field B: \Phi(z) = e/|z| [ 1- exp(-\sqrt{6m_e^2}|z|) + exp(-\sqrt{(2/\pi) e^3 B + 6m_e^2} |z|) ]. The deviation from Coulomb's law becomes essential for B > 3\pi B_{cr}/\alpha = 3 \pi m_e^2/e^3 \approx 6 10^{16} G. In such superstrong fields, electrons are ultra-relativistic except those which occupy the lowest Landau level (LLL) and which have the energy epsilon_0^2 = m_e^2 + p_z^2. The energy spectrum on which LLL splits in the presence of the atomic nucleus is found analytically. For B > 3 \pi B_{cr}/\alpha, it substantially differs from the one obtained without accounting for the modification of the atomic potential.Comment: version to be published in Physical Review D (incorrect "Keywords" in previous version have been cancelled

Critical nucleus charge in a superstrong magnetic field: effect of screening

A superstrong magnetic field stimulates the spontaneous production of positrons by naked nuclei by diminishing the value of the critical charge Z_{cr} . The phenomenon of screening of the Coulomb potential by a superstrong magnetic field which has been discovered recently acts in the opposite direction and prevents the nuclei with Z52 for a nucleus to become critical stronger B are needed than without taking screening into account.Comment: 13 pages, 2 figures, version to be published in Physical Review

Atomic levels in superstrong magnetic fields and D=2 QED of massive electrons: screening

The photon polarization operator in superstrong magnetic fields induces the dynamical photon "mass" which leads to screening of Coulomb potential at small distances $z\ll 1/m$, $m$ is the mass of an electron. We demonstrate that this behaviour is qualitatively different from the case of D=2 QED, where the same formula for a polarization operator leads to screening at large distances as well. Because of screening the ground state energy of the hydrogen atom at the magnetic fields $B \gg m^2/e^3$ has the finite value $E_0 = -me^4/2 \ln^2(1/e^6)$.Comment: 12 pages, 2 figure

Two-Point Correlators of Fermionic Currents in External Magnetic Field

We study the two-point correlation functions under an influence of the constant homogeneous magnetic field. In addition to the correlators of scalar, pseudoscalar, vector and axial-vector fermionic currents, we calculate the non-diagonal one including the tensor and pseudoscalar currents. The tensor current is a fermionic part of the Pauli Lagrangian relevant for the electromagnetic interaction of fermions through the anomalous magnetic moment. Its contribution to the photon polarization operator is briefly discussed

Real and virtual photons in an external constant electromagnetic field of most general form

The photon behavior in an arbitrary superposition of constant magnetic and electric fields is considered on most general grounds basing on the first principles like Lorentz- gauge- charge- and parity-invariance. We make model- and approximation-independent, but still rather informative, statements about the behavior that the requirement of causal propagation prescribes to massive and massless branches of dispersion curves, and describe the way the eigenmodes are polarized. We find, as a consequence of Hermiticity in the transparency domain, that adding a smaller electric field to a strong magnetic field in parallel to the latter causes enhancement of birefringence. We find the magnetic field produced by a point electric charge far from it (a manifestation of magneto-electric phenomenon). We establish degeneracies of the polarization tensor that (under special kinematic conditions) occur due to space-time symmetries of the vacuum left after the external field is imposed.Comment: 30 pages, 1 figure, 57 equations, reference list of 38 item

Оптимизация инфузионной терапии в плановой абдоминальной хирургии

Purpose. Evaluation of the influence of intra-operative targeted infusion therapy managed by the monitoring of stroke volume variability on post-operative results of major surgeries of gastrointestinal organs.Materials and Methods. The prospective study included 80 patients subjected to selective operative interventions of abdominal organs involving entero-enteroanastomosis. In the experimental group (n=39), the infusion therapy was conducted according to the developed targeted therapy protocol, of which the key parameter was stroke volume variability. In the control group (n=41), infusion therapy was conducted based on routine hemodynamic monitoring (average arterial pressure, heart rate, blood loss level with regard to intra-operative situation). In both groups, operative intervention was carried out in identical conditions (combined anesthesia, identical drugs to induce and maintain anesthesia); the only differences included infusion therapy.Results. In the experimental group versus the control group the intra-operative infusion volume was smaller, the number of patients with complications and the total number of complications were reliably lower, and the gastrointestinal tract functional recovery occurred earlier. Conclusion. A targeted infusion therapy based on a stroke volume variability monitoring as the key parameter allows optimizing the infusion load and facilitates reduction of the number of patients with complications and earlier recovery of gastrointestinal tract functions after major operative abdominal interventions.Цель исследования — оценка влияния интраоперационной целенаправленной инфузионной терапии, управляемой на основании мониторинга вариабельности ударного объема, на послеоперационные результаты больших хирургических вмешательств на органах желудочно-кишечного тракта.Материалы и методы. В проспективное исследование включили 80 пациентов, подвергшихся плановым оперативным вмешательствам на органах брюшной полости с формированием межкишечного анастомоза. В группе исследования (n=39) проводили инфузионную терапию, согласно разработанному протоколу целенаправленной терапии, ключевым параметром которого являлась вариабельность ударного объема. В контрольной группе (n=41) инфузионную терапию проводили на основании данных рутинного мониторинга гемодинамики (среднее артериальное давление, частота сердечных сокращений, степень кровопотери с учетом интраоперационной ситуации). В обеих группах оперативное вмешательство проводили в идентичных условиях (сочетанная анестезия, идентичные препараты для индукции и поддержания анестезии), разница заключалась в подходе к инфузионной терапии.Результаты. В группе исследования в сравнении с контрольной группой, интраоперационный объем инфузии был меньше, достоверно ниже было число пациентов с осложнениями и общее количество осложнений, а восстановление функций желудочно-кишечного тракта происходило в более ранние сроки.Заключение. Целенаправленная инфузионная терапия, базирующаяся на мониторинге вариабельности ударного объема в качестве ключевого параметра, позволяет оптимизировать инфузионную нагрузку и способствует снижению числа пациентов с осложнениями, а также более раннему восстановлению функций желудочно-кишечного тракта после больших хирургических абдоминальных вмешательств