Observation of superluminal geometrical resonances in Bi2Sr2CaCu2O8+x intrinsic Josephson junctions

We study Fiske steps in small Bi2Sr2CaCu2O8+x mesa structures, containing only few stacked intrinsic Josephson junctions. Careful alignment of magnetic field prevents penetration of Abrikosov vortices and facilitates observation of a large variety of high quality geometrical resonances, including superluminal with velocities larger than the slowest velocity of electromagnetic waves. A small number of junctions limits the number of resonant modes and allows accurate identification of modes and velocities. It is shown that superluminal geometrical resonances can be excited by subluminal fluxon motion and that flux-flow itself becomes superluminal at high magnetic fields. We argue that observation of high-quality superluminal geometrical resonances is crucial for realization of the coherent flux-flow oscillator in the THz frequency range

The current state of the issues of diagnosis and surgical treatment of liver echinococcosis (literature review)

The article presents a review of literature data in order to study current problems in the diagnosis and surgical treatment of liver echinococcosis. At the present stage of technological progress, it is possible to study the genetic, anatomical and pathophysiological aspects of echinococcosis. The article highlights the advantages and disadvantages of surgical operations performed in patients with echinococcal liver damage. Methods and results of surgical treatment in various clinics are considered. The main surgical directions in the treatment of parasitic liver damage have been determined. These are more radical anatomical and extensive liver resections and minimally invasive, including laparoscopic and robotic techniques. Each of the methods used has its own niche of application and its own limitations. An opinion is expressed about the prospects for the development of minimally invasive methods of surgical treatment. The authors note the actual absence of a unified standardized tactics of surgical treatment at the moment. It is noted that the literature contains only fragmentary data on the possibility of combining minimally invasive and classical methods of surgical treatment. Despite the introduction of new methods of treatment, the percentage of complications and mortality are still high. Thus, the lack of uniform diagnostic standards and principles for determining surgical tactics testifies to the urgency of the problem of treating parasitic liver damage and determines the search for new solutions in order to improve the results of surgical treatment of this pathology

Dynamics of Asymptotic Diffeomorphisms in (2+1)-Dimensional Gravity

In asymptotically anti-de Sitter gravity, diffeomorphisms that change the conformal boundary data can be promoted to genuine physical degrees of freedom. I show that in 2+1 dimensions, the dynamics of these degrees of freedom is described by a Liouville action, with the correct central charge to reproduce the entropy of the BTZ black hole.Comment: 8 pages, LaTeX; v2: slightly expanded discussion of implications, more references; v3: more explicit comparison to Chern-Simons approach and discussion of role of constraints; v4: added discussion of relationships to and differences with earlier work, new and corrected reference

On the Boundary Dynamics of Chern-Simons Gravity

We study Chern-Simons theory with a complex G_C or a real G x G gauge group on a manifold with boundary - this includes Lorentzian and Euclidean (anti-) de Sitter (E/A)dS gravity for G=SU(2) or G=SL(2,R). We show that there is a canonical choice of boundary conditions that leads to an unambiguous, fully covariant and gauge invariant, off-shell derivation of the boundary action - a G_C/G or G WZW model, coupled in a gauge invariant way to the boundary value of the gauge field. In particular, for (E/A)dS gravity, the boundary action is a WZW model with target space (E/A)dS_3, reminiscent of a worldsheet for worldsheet mechanism. We discuss in some detail the properties of the boundary theories that arise and we confront our results with various related constructions in the literature.Comment: 22 pages, LaTeX2e, v2: JHEP3.cls, references and a footnote adde

A case of successful multi-stage surgical treatment of liver echinococcosis

A clinical case of successful radical multi-stage surgical treatment of a patient with bilobar parasitic lesion of the liver with echinococcosis complicated by infection of one of the cysts is presented. The patient was admitted to the clinic with volumetric lesions in both lobes of the liver. At the stage of differential diagnosis, on the basis of process verification by puncture biopsy under ultrasound control, the ethiology of mass lesions was reliably established. At the primary stationary stage, infection of one of the echinococcal cysts was diagnosed, for which the cyst was drained under ultrasound control. After that, the patient was discharged to the outpatient care for compensation, correction of the general level of health and nutritional status. At the next stage of the inpatient examination, the patient was determined to have an insufficient level of functional reserves of the liver to perform a radical operation. For this reason, laparoscopic ligation of the right branch of the portal vein was performed in order to develop vicarious hypertrophy of the contralateral lobe. After 30 days, the increased level of functional reserves of the liver made it possible to plan radical surgical treatment with an acceptable risk for the patient. The operation was performed in the amount of right-sided extended hemihepatectomy with marginal resection of the 3rd segment of the liver. The symptoms of liver failure in the postoperative period according to the ISGLS scale were regarded as Grade A. The patient was discharged from the hospital in a satisfactory condition on day 10 after the operation. In the postoperative period, courses of therapy with albendazole were prescribed according to the standard scheme. The patient is under observation for more than a year after treatment. The condition is satisfactory. No recurrence of the disease was noted