Two weeks delayed bleeding in blunt liver injury: case report and review of the literature

Most cases of blunt hepatic trauma are treated nowadays non-operatively. This type of conservative treatment has resulted in increased complication rate. Delayed complications occur in cases that didn't require surgical intervention during the first 24 hours. The most common late complication is hemorrhage. We report a case of two weeks delayed hemorrhage after blunt hepatic trauma in an adult. We describe the diagnostic procedures, the surgical treatment and review the relevant literature

Acute cholecystitis managed in a rural surgical department

ObjectivesTo define the outcome over a prolonged period of an unselected cohort of patients presenting with acute cholecystitis (AC) to a 560 bed rural hospital in Israel.Design, setting and participantsRetrospective case series analysed from a single referral centre between 2006 and 2015. Separated into Group 1 managed by emergent cholecystectomy, Group 2 treated with antibiotics and delayed cholecystectomy, Group 3 treated with percutaneous cholecystostomy (PC) and selected delayed cholecystectomy and Group 4 managed entirely conservatively with no subsequent cholecystectomy.Methods Assessment of complication rates: in-hospital and delayed cause-specific morbidity and mortality along with conversion rates and the risk of intraoperative stone spillage. Results Of 321 patients hospitalized for AC, there were 50 in Group 1, 68 in Group 2, 59 in Group 3 and 98 in Group 4. Group 3 were older with more comorbidities and when coming to surgery had more open conversions. Intraoperative stone spillage was more common in Groups 2 and 3. The length of hospital stay was greater for Groups 1 and 3. Of the Group 4 cases, 63.2 per cent remained asymptomatic over a median follow-up of 78 months. Of those with recurrent biliary symptoms, 58.3 per cent were ASA Grade III/IV with 25/36 late deaths 80 per cent of which were from non-biliary causes. ConclusionIn the management of AC, early cholecystectomy is favored with non-operative approaches like PC drainage or antibiotic treatment alone being reserved for frailer comorbid cases. The absolute need for subsequent cholecystectomy is not supported by this series and requires further investigation

Is it the boundaries or disorder that dominates electron transport in semiconductor `billiards'?

Semiconductor billiards are often considered as ideal systems for studying dynamical chaos in the quantum mechanical limit. In the traditional picture, once the electron's mean free path, as determined by the mobility, becomes larger than the device, disorder is negligible and electron trajectories are shaped by specular reflection from the billiard walls alone. Experimental insight into the electron dynamics is normally obtained by magnetoconductance measurements. A number of recent experimental studies have shown these measurements to be largely independent of the billiards exact shape, and highly dependent on sample-to-sample variations in disorder. In this paper, we discuss these more recent findings within the full historical context of work on semiconductor billiards, and offer strong evidence that small-angle scattering at the sub-100 nm length-scale dominates transport in these devices, with important implications for the role these devices can play for experimental tests of ideas in quantum chaos.Comment: Submitted to Fortschritte der Physik for special issue on Quantum Physics with Non-Hermitian Operator

The survival probability and the local density of states for one-dimensional Hamiltonian systems

For chaotic systems there is a theory for the decay of the survival probability, and for the parametric dependence of the local density of states. This theory leads to the distinction between "perturbative" and "non-perturbative" regimes, and to the observation that semiclassical tools are useful in the latter case. We discuss what is "left" from this theory in the case of one-dimensional systems. We demonstrate that the remarkably accurate {\em uniform} semiclassical approximation captures the physics of {\em all} the different regimes, though it cannot take into account the effect of strong localization.Comment: 17 pages, 2 figures, textual improvement

Random Matrix Theories in Quantum Physics: Common Concepts

We review the development of random-matrix theory (RMT) during the last decade. We emphasize both the theoretical aspects, and the application of the theory to a number of fields. These comprise chaotic and disordered systems, the localization problem, many-body quantum systems, the Calogero-Sutherland model, chiral symmetry breaking in QCD, and quantum gravity in two dimensions. The review is preceded by a brief historical survey of the developments of RMT and of localization theory since their inception. We emphasize the concepts common to the above-mentioned fields as well as the great diversity of RMT. In view of the universality of RMT, we suggest that the current development signals the emergence of a new "statistical mechanics": Stochasticity and general symmetry requirements lead to universal laws not based on dynamical principles.Comment: 178 pages, Revtex, 45 figures, submitted to Physics Report