Portal vein grafts in hepatic transplantation

Confirmation of patency of the portal vein by either ultrasound or angiography is a routine part of the evaluation of patients being considered for hepatic transplantation. Complete thrombosis of the portal vein usually has been viewed as precluding successful orthotopic hepatic replacement. In addition, some pediatric patients present with extremely small portal veins which, although patent, have proved to be thick walled and sclerotic. Our recent experience has shown that, in both of these situations, successful and complete revascularization of hepatic allografts is quite feasible by using a vein graft to ensure adequate portal venous flow

Anomalous local magnetic field distribution and strong pinning in CaFe1.94Co0.06As2 single crystals

Magneto-optical imaging of a single crystal of CaFe1.94Co0.06As2, shows anomalous remnant magnetization within Meissner like regions of the superconductor. The unconventional shape of the local magnetization hysteresis loop suggests admixture of superconducting and magnetic fractions governing the response. Near the superconducting transition temperature, local magnetic field exceeds the applied field resulting in a diamagnetic to positive magnetization transformation. The observed anomalies in the local magnetic field distribution are accompanied with enhanced bulk pinning in the CaFe1.94Co0.06As2 single crystals. We propose our results suggest a coexistence of superconductivity and magnetic correlations.Comment: 6 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1201.369

Critical behavior at de-pinning of a driven disordered vortex matter in 2H-NbS2

We report unusual jamming in driven ordered vortex flow in 2H-NbS2. Reinitiating movement in these jammed vortices with a higher driving force, and halting it thereafter once again with a reduction in drive, unfolds a critical behavior centered around the de-pinning threshold via divergences in the lifetimes of transient states, validating the predictions of a recent simulation study, which also pointed out a correspondence between plastic de-pinning in vortex matter and the notion of random organization proposed in the context of sheared colloids undergoing diffusive motion.Comment: Phys. Rev. B (in press, 2012). The paper has 14 pages of Text+ Refs. with 4 figures. (Note as some of the figure files are large in size, to enable faster download, the file size has been kept small and the figure resolution are low. The online version of the paper to appear in PRB will contain the higher resolution figures