The incidence of portal vein thrombosis at liver transplantation

The incidence of portal vein thrombosis was examined in 885 patients who received orthotopic liver transplantations for various end‐stage liver diseases between 1989 and 1990. The thrombosis was classified into four grades. Grade 1 was thrombosis of intrahepatic portal vein branches, grade 2 was thrombosis of the right or left portal branch or at the bifurcation, grade 3 was partial obstruction of the portal vein trunk, and grade 4 was complete obstruction of the portal vein trunk. Among the 849 patients without previous portosystemic shunt, 14 patients (1.6%) had grade 1, 27 patients (3.2%) had grade 2, 27 patients (3.2%) had grade 3 and 49 patients (5.8%) had grade 4 portal vein thrombosis. The incidence of portal vein thrombosis was highest (34.8%) in the patients with hepatic malignancy in the cirrhotic liver, followed by those with Budd‐Chiari syndrome (22.2%) and postnecrotic cirrhosis of various causes (15.7%). The patients with encephalopathy, ascites, variceal bleeding, previous splenectomy and small liver had significantly higher incidences of portal vein thrombosis than the others. The total incidence of portal vein thrombosis among the 36 patients with previous portosystemic shunt was 38.9%, which was significantly higher than that (13.8%) of those without shunt. (HEPATOLOGY 1992;16;1195–1198.) Copyright © 1992 American Association for the Study of Liver Disease

Current induced magnetization reversal on the surface of a topological insulator

We study dynamics of the magnetization coupled to the surface Dirac fermions of a three di- mensional topological insulator. By solving the Landau-Lifshitz-Gilbert equation in the presence of charge current, we find current induced magnetization dynamics and discuss the possibility of mag- netization reversal. The torque from the current injection depends on the transmission probability through the ferromagnet and shows nontrivial dependence on the exchange coupling. The mag- netization dynamics is a direct manifestation of the inverse spin-galvanic effect and hence another ferromagnet is unnecessary to induce spin transfer torque in contrast to the conventional setup.Comment: 4 pages, 4 figure

Dynamics of magnetization on the topological surface

We investigate theoretically the dynamics of magnetization coupled to the surface Dirac fermions of a three dimensional topological insulator, by deriving the Landau-Lifshitz-Gilbert (LLG) equation in the presence of charge current. Both the inverse spin-Galvanic effect and the Gilbert damping coefficient $\alpha$ are related to the two-dimensional diagonal conductivity $\sigma_{xx}$ of the Dirac fermion, while the Berry phase of the ferromagnetic moment to the Hall conductivity $\sigma_{xy}$. The spin transfer torque and the so-called $\beta$-terms are shown to be negligibly small. Anomalous behaviors in various phenomena including the ferromagnetic resonance are predicted in terms of this LLG equation.Comment: 4+ pages, 1 figur

Growth rates of lava domes with respect to viscosity of magmas

In the discussion of lava dome formation, viscosity of magma plays an important role. Measurements of viscosity of magmas in field and laboratory are briefly summarized. The types of lava dome emplacements are classified into two, squeeze- and spine-type, by kinetic processes. The squeeze-type is the formation of a dome as a result of squeezes of magma through conduits and the latter is solidified magma forced to ascend by underlying fluid magma. An important parameter in the formation of such lava domes is their growth rates. Lava domes of squeeze-type are governed by the Hagen-Poiseuille Law which involves their viscosoties and other eruption parameters. At present, the real viscosity of magmas at the site of lava dome is still inaccessible. In order to avoid uncertainty in viscosity of magmas, a conception of «macroscopic viscosity» is proposed, which involves effects of chemical components, mainly SiO2 and volatile material, crystals and temperature, and their changes with time. Lava dome formations during the 20th century are briefly examined and their growth rates are estimated. The relationship between the growth rates and the SiO2 content of the magma is statistically studied, and the macroscopic viscosity is empirically expressed as a function of SiO2 content. The linearity between the two parameters is reasonably interpreted. This means that formation processes of lava domes are dominantly controlled by macroscopic viscosity of magma

Spin-current absorption by inhomogeneous spin-orbit coupling

We investigate the spin-current absorption induced by an inhomogeneous spin-orbit coupling due to impurities in metals. We consider the system with spin currents driven by the electric field or the spin accumulation. The resulting diffusive spin currents, including the gradient of the spin-orbit coupling strength, indicate the spin-current absorption at the interface, which is exemplified with experimentally relevant setups.Comment: 13 pages, 5 figure

Charge transport in two dimensional electron gas/superconductor junctions with Rashba spin-orbit coupling

We have studied the tunneling conductance in two dimensional electron gas / insulator / superconductor junctions in the presence of Rashba spin-orbit coupling (RSOC). It is found that for low insulating barrier the tunneling conductance is suppressed by the RSOC while for high insulating barrier it is almost independent of the RSOC. We also find the reentrant behavior of the conductance at zero voltage as a function of RSOC for intermediate insulating barrier strength. The results are essentially different from those predicted in ferromagnet / superconductor junctions. The present derivation of the conductance is applicable to arbitrary velocity operator with off-diagonal components.Comment: 8 pages, 6 figure

Theory of Josephson effect in chiral p-wave superconductor / diffusive normal metal / chiral p-wave superconductor junctions

We study the Josephson effect between chiral p-wave superconductor / diffusive normal metal (DN) / chiral p-wave superconductor (CP/DN/CP) junctions using quasiclassical Green's function formalism with proper boundary conditions. The px+ipy-wave symmetry of superconducting order parameter is chosen which is believed to be a pairing state in Sr2RuO4. It is shown that the Cooper pairs induced in DN have an odd-frequency spin-triplet s-wave symmetry, where pair amplitude is an odd function of Matsubara frequency. Despite the peculiar symmetry properties of the Cooper pairs, the behavior of the Josephson current is rather conventional. We have found that the current phase relation is almost sinusoidal and the Josephson current is proportional to exp(-L/xi), where xi is the coherence length of the Cooper pair in DN and L is the length of DN. The Josephson current between CP / diffusive ferromagnet metal (DF) / CP junctions is also calculated. It is shown that the 0-pi transition can be realized by varying temperature or junction length L similar to the case of conventional s-wave junctions. These results may serve as a guide to study superconducting state of Sr2RuO4.Comment: 9 pages, 9 figure

Arterial Mycotic Aneurysm and Rupture: A Potentially Fatal Complication of Pancreas Transplantation in Diabetes Mellitus

• Mycotic aneurysm at the site of a Carrel patch arterial anastomosis occurred in four patients who had undergone whole pancreas transplantation 2.5 to 14.5 months previously. In all patients, the graft had been removed, leaving the Carrel patch on the iliac artery. The aneurysms ruptured into the intestine or the extraperitoneal space. The ruptures were sudden and life-threatening in three of four cases. This diagnosis must be suspected in patients with a history of pancreas transplantation in the immediate or distant past if they present with unexplained hypotension, cardiac arrest, or gastrointestinal tract bleeding. © 1989, American Medical Association. All rights reserved