Results of surgical treatment of postinfarction left ventricular aneurysm complicated with ventricular tachycardia with use of 3D-navigation system CARTO™

The aim of the research was to study localization of wandering focus and effectiveness of extensive endocardectomy at left ventricular reconstruction in patients with ischemic heart disease (IHD) with postinfarction left ventricular aneurysm (LVA) in combination with ventricular tachycardia (VT). Examined patients besides diagnostic routines had intracardiac electrophysiological examination (EPE) with use of 3D-navigation system CARTOTX (Biosense Webster). During EPE abnormal zones of delayed navigating and zones of double potential with main localization in the area of cacuminal and middle septate segments were found. All patients were divided into two groups: patients of the first group had aortocoronary bypass (ACB) in combination with left ventricular reconstruction completed with extended resection of endocardium with pinch of all cacuminal and middle septate segments; 2 patients of the second group had isolated ACB, 2 patients had ACB with mitral annuloplasty with rim and de Vega plasty of tricuspid valve, 1 patient had percutaneous transluminal coronary angioplasty, 10 patients hadACB in combination with LVA plasty without extended endocardium resection. As the result of the treatment in the first group there were no VT episodes after resection of aneurysm with extended endocardium resection; 33 % of patients in the second group had implantable cardioverter defibrillator, 7 % of the patients had radio frequency ablation of VT nidus, 7 % of the patients had anti-arrhythmic therapy. Taking into consideration that main localization of ectopic nidus in patients with IHD with postinfarction LVA and VT is in the area of cacuminal and middle septate segments, left ventricular reconstruction in these patients needs to be conducted with extended resection of endocardium of these segments

Our experience of surgical treatment of aortic arch obstruction in children in the presence of antegrade selective cerebral perfusion

This work is about outcomes of surgical treatment aortic arch obstruction in children performed with the use of selective cerebral perfusion and moderate hypothermia. The study included 97 patients with aortic coarctation, recoarctation and hypoplastic aortic arch. The patients were divided into 3 groups. 75 patients with isolated coarctation and recoarctation or with concomitant atrial septal defects, patentforamen ovale and patent ductus arterious were assigned to the 1st group. The 2nd group included 13 patients with aortic arch obstruction and ventricular septal defects. The 3rd group consisted of 9 patients with coarctation, recoarctation and complex intracardiac anomalies. All patients underwent reconstruction of the aortic arch with selective cerebral perfusion and moderate hypothermia. Overall mortality rate was 4%. Postoperative complications took place in 7% of the cases: 1% - postoperative bleeding, 1% - paresis of the diaphragm, 2% - pneumothorax, 2% - chylothorax, and 1% of the cases - vocal cords paresis. Respiratory postoperative complications were registered in 5% of cases. In 6% of the cases patients had neurological postoperative complications. After the operation there was no gradientfound between the pressures on upper and lower extremities. We consider that antegrade selective cerebral perfusion and moderate hypothermia during aortic arch reconstruction are effective methods of brain and visceral organs protection

Photofission of heavy nuclei at energies up to 4 GeV

Total photofission cross sections for 238U, 235U, 233U, 237Np, 232Th, and natPb have been measured simultaneously, using tagged photons in the energy range Egamma=0.17-3.84 GeV. This was the first experiment performed using the Photon Tagging Facility in Hall B at Jefferson Lab. Our results show that the photofission cross section for 238U relative to that for 237Np is about 80%, implying the presence of important processes that compete with fission. We also observe that the relative photofission cross sections do not depend strongly on the incident photon energy over this entire energy range. If we assume that for 237Np the photofission probability is equal to unity, we observe a significant shadowing effect starting below 1.5 GeV.Comment: 4 pages of RevTex, 6 postscript figures, Submitted to Phys. Rev. Let

PROSPECTS FOR THE DEVELOPMENT OF PEDIATRIC CARDIOVASCULAR SURGERY IN THE BURYAT REPUBLIC

The article describes the demographic situation, the status of neonatal, children cardiological and cardiosurgery cares in the Buryat Republic. The information gathered by main non-staff experts of appropriate specializations proves the necessity of cardiosurgical care to the children population, identifies the structure of heart defects, the volume of cardiosurgical care provided to patients with congenital heart diseases in the region and outside of the region during from 2013 to 2015, preoperative and postoperative mortality. In addition, the article represents diagnostic capabilities of one of the largest medical institutions of the Buryat Republic as a potential station for delivery of cardiosurgical care for patients with congenital anomalies of cardiovascular system and suggests ways to optimize the care of children with congenital heart disease

Mutual heavy ion dissociation in peripheral collisions at ultrarelativistic energies

We study mutual dissociation of heavy nuclei in peripheral collisions at ultrarelativistic energies. Earlier this process was proposed for beam luminosity monitoring via simultaneous registration of forward and backward neutrons in zero degree calorimeters at Relativistic Heavy Ion Collider. Electromagnetic dissociation of heavy ions is considered in the framework of the Weizsacker-Williams method and simulated by the RELDIS code. Photoneutron cross sections measured in different experiments and calculated by the GNASH code are used as input for the calculations of dissociation cross sections. The difference in results obtained with different inputs provides a realistic estimation for the systematic uncertainty of the luminosity monitoring method. Contribution to simultaneous neutron emission due to grazing nuclear interactions is calculated within the abrasion model. Good description of CERN SPS experimental data on Au and Pb dissociation gives confidence in predictive power of the model for AuAu and PbPb collisions at RHIC and LHC.Comment: 46 pages with 7 tables and 13 figures, numerical integration accuracy improved, next-to-leading-order corrections include

Particle emission following Coulomb excitation in ultrarelativistic heavy-ion collisions

We study nuclear reactions induced by virtual photons associated with Lorentz-boosted Coulomb fields of ultrarelativistic heavy ions. Evaporation, fission and multifragmentation mechanisms are included in a new RELDIS code, which describes the deexcitation of residual nuclei formed after single and double photon absorption in peripheral heavy-ion collisions. Partial cross sections for different dissociation channels, including the multiple neutron emission ones, are calculated and compared with data when available. Rapidity and transverse momentum distributions of nucleons, nuclear fragments and pions, produced electromagnetically, are also calculated. These results provide important information for designing large-rapidity detectors and zero-degree calorimeters at RHIC and LHC. The electromagnetic dissociation of nuclei imposes some constrains on the investigation of exotic particle production in gamma-gamma fusion reactions.Comment: 26 LaTeX pages including 8 figures, uses epsf.st

Level density and thermal properties in rare earth nuclei

A convergent method to extract the nuclear level density and the gamma-ray strength function from primary gamma-ray spectra has been established. Thermodynamical quantities have been obtained within the microcanonical and canonical ensemble theory. Structures in the caloric curve and in the heat capacity curve are interpreted as fingerprints of breaking of Cooper pairs and quenching of pairing correlations. The strength function can be described using models and common parameterizations for the E1, M1 and pygmy resonance strength. However, a significant decrease of the pygmy resonance strength at finite temperatures has been observed.Comment: 15 pages including 8 figures. Proceedings article for the conference Nuclear Structure and Related Topics, Dubna, Russia, June 6-10, 200

Combinatorial nuclear level density by a Monte Carlo method

We present a new combinatorial method for the calculation of the nuclear level density. It is based on a Monte Carlo technique, in order to avoid a direct counting procedure which is generally impracticable for high-A nuclei. The Monte Carlo simulation, making use of the Metropolis sampling scheme, allows a computationally fast estimate of the level density for many fermion systems in large shell model spaces. We emphasize the advantages of this Monte Carlo approach, particularly concerning the prediction of the spin and parity distributions of the excited states, and compare our results with those derived from a traditional combinatorial or a statistical method. Such a Monte Carlo technique seems very promising to determine accurate level densities in a large energy range for nuclear reaction calculations.Comment: 30 pages, LaTex, 7 figures (6 Postscript figures included). Fig. 6 upon request to the autho

Inclusive meson production in peripheral collisions of ultrarelativistic heavy ions

There exist several proposals to use Weizs\"{a}cker-Williams photons generated by ultrarelativistic heavy ions to produce exotic particles in $\gamma\gamma$ fusion reactions. To estimate the background conditions for such reactions we analyze various mechanisms of meson production in very peripheral collisions of ultrarelativistic heavy ions at RHIC and LHC energies. Besides $\gamma\gamma$ fusion they include also electromagnetic $\gamma A$ interactions and strong nucleon-nucleon interactions in grazing $AA$ collisions. All these processes are characterised by low multiplicities of produced particles. $\gamma A$ and $AA$ events are simulated by corresponding Monte Carlo codes, RELDIS and FRITIOF. In each of these processes a certain fraction of pions is produced close to the mid-rapidity region that gives a background for the $\gamma\gamma$ events. The possibility of selecting mesons produced in $\gamma\gamma$ fusion events via different $p_t$ cut procedures is demonstrated.Comment: 27 pages with 4 eps-figures included, uses axodraw.sty Tab.2 and 3 correcte

Spallation reactions. A successful interplay between modeling and applications

The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie