Hepatic trisegmentectomy and other liver resections

Trisegmentectomy, extended right hepatic lobectomy, is the removal of the true right lobe of the liver in continuity with most or all of the medial segment of the left lobe. Some important features of the operation have not been well described previously. To perform trisegmentectomy, safely, a fusion of liver tissue covering the umbilical fissure at the level of the falciform ligament must first be split open in many patients. The left branches of the portal triad structures are mobilized from the undersurface of the liver nearly to but not into the umbilical fissure. The blood supply and duct drainage of the medial segment originate within the umbilical fissure and feed back toward the right side buried in liver substance. They are found with blunt dissection just to the right of the flaciform ligament, encircled and ligated. Failure to appreciate this switch back anatomic arrangement may lead to injury of the blood supply or biliary drainage of the residual lateral segment. Parenthetically, the mirror image operation of lateral segmentectomy could result in devascularization of the medial segment if dissection and ligation were performed within the umbilical fissure instead of well to the left of this landmark. In most trisegmentectomies, the left portion of the caudate lobe is not removed. This small piece of tissue is interposed between the lateral segment and the inferior vena cava into which it drains by small tributaries. If the left portion of the caudate lobe is to be excised, it is necessary to ligate the last two posteriorly running branches before the main left trunks of the portal triad structures reach the umbilical fissure. Once this step is taken and if the caudate removal is completed, the remaining lateral segment usually has only one remaining outflow, that of the left hepatic vein. The other principles of trisegmentectomy are the same as with less radical subtotal hepatic resection. These include vascular suture closure of the main outflow veins, avoidance of parasegmental planes that leave behind a strip of devitalized tissue, preservation of intersegmental or interlobar veins, omission of techniques that sew shut or otherwise cover the raw surface of the remnant and provision of adequate drainage of dead space. After trisegmentectomy and also after true lobectomy, this last objective is usually met by leaving part of the operative incision open. Using thse guidelines, there has been no mortality with 27 hepatic resections carried out since 1963, including 14 trisegmentectomies

Hepatic transplantation, 1975.

This report reviews experience with 97 patients given liver transplants. We regard out survival statistics as unsatisfactory, but fell they should encourage further work since 22 patients have survived at least one year with a maximum survival of 5 13 YEARS. The Achilles' heel of liver transplantation os bile duct reconstruction. We presently rely upon Roux-en-Y reconstruction, or alternatively, duct-to-duct anastomosis with a T-tube stent. The prime indication for liver replacement is non-neoplastic liver disease, but a favourable malignancy for treatment may prove to be small intrahepatic duct cell carcinomas

Entering the "foxhole": Partisan media priming and the application of racial justice in America

Can accessing a partisan media environment—irrespective of its content—change how Americans interpret and assess news? We examine this question by focusing on one of the most fraught issues in American society: racial justice. Although studies suggest that repeated exposure to right-leaning media messaging can amplify racial resentment, we leverage a pair of survey experiments to test whether merely seeing a conservative media masthead can make Whites render justice with racialized considerations. Results show that—even keeping the content of stories identical—entering a simulated right-leaning media environment significantly conditions racial attitudes. We find evidence of both anti-Black and pro-White biases that are activated when respondents consume information under the Fox News masthead. This study has important implications for understanding how partisan media priming shapes political views and the distinctive nature of racism in America

Electron gyroscale fluctuation measurements in National Spherical Torus Experiment H-mode plasmas

A collective scattering system has measured electron gyroscale fluctuations in National Spherical Torus Experiment [M. Ono et al., Nucl. Fusion 40, 557 (2000)] H-mode plasmas to investigate electron temperature gradient (ETG) turbulence. Observations and results pertaining to fluctuation measurements in ETG-stable regimes, the toroidal field scaling of fluctuation amplitudes, the relation between fluctuation amplitudes and transport quantities, and fluctuation magnitudes and k-spectra are presented. Collectively, the measurements provide insight and guidance for understanding ETG turbulence and anomalous electron thermal transport. (C) 2009 American Institute of Physics. [doi:10.1063/1.3262530]X116sciescopu

Air-sea transfer of gas phase controlled compounds

Gases in the atmosphere/ocean have solubility that spans several orders of magnitude. Resistance in the molecular sublayer on the waterside limits the air-sea exchange of sparingly soluble gases such as SF6 and CO2. In contrast, both aerodynamic and molecular diffusive resistances on the airside limit the exchange of highly soluble gases (as well as heat). Here we present direct measurements of air-sea methanol and acetone transfer from two open cruises: the Atlantic Meridional Transect in 2012 and the High Wind Gas Exchange Study in 2013. The transfer of the highly soluble methanol is essentially completely airside controlled, while the less soluble acetone is subject to both airside and waterside resistances. Both compounds were measured concurrently using a proton-transfer-reaction mass spectrometer, with their fluxes quantified by the eddy covariance method. Up to a wind speed of 15 m s-1, observed air-sea transfer velocities of these two gases are largely consistent with the expected near linear wind speed dependence. Measured acetone transfer velocity is ~30% lower than that of methanol, which is primarily due to the lower solubility of acetone. From this difference we estimate the "zero bubble" waterside transfer velocity, which agrees fairly well with interfacial gas transfer velocities predicted by the COARE model. At wind speeds above 15 m s-1, the transfer velocities of both compounds are lower than expected in the mean. Air-sea transfer of sensible heat (also airside controlled) also appears to be reduced at wind speeds over 20 m s-1. During these conditions, large waves and abundant whitecaps generate large amounts of sea spray, which is predicted to alter heat transfer and could also affect the air-sea exchange of soluble trace gases. We make an order of magnitude estimate for the impacts of sea spray on air-sea methanol transfer

Short-scale turbulent fluctuations driven by the electron-temperature gradient in the national spherical torus experiment

Measurements with coherent scattering of electromagnetic waves in plasmas of the National Spherical Torus Experiment indicate the existence of turbulent fluctuations in the range of wave numbers k(perpendicular to)rho(e)=0.1-0.4, corresponding to a turbulence scale length nearly equal to the collisionless skin depth. Experimental observations and agreement with numerical results from a linear gyrokinetic stability code support the conjecture that the observed turbulence is driven by the electron-temperature gradient.X1155sciescopu

Observations of Reduced Electron Gyroscale Fluctuations in National Spherical Torus Experiment H-Mode Plasmas with Large E X B Flow Shear

Electron gyroscale fluctuation measurements in National Spherical Torus Experiment H-mode plasmas with large toroidal rotation reveal fluctuations consistent with electron temperature gradient (ETG) turbulence. Large toroidal rotation in National Spherical Torus Experiment plasmas with neutral beam injection generates ExB flow shear rates comparable to ETG linear growth rates. Enhanced fluctuations occur when the electron temperature gradient is marginally stable with respect to the ETG linear critical gradient. Fluctuation amplitudes decrease when the ExB flow shear rate exceeds ETG linear growth rates. The observations indicate that ExB flow shear can be an effective suppression mechanism for ETG turbulence.X1129sciescopu

Internal transport barriers in the National Spherical Torus Experiment

In the National Spherical Torus Experiment [M. Ono , Nucl. Fusion 41, 1435 (2001)], internal transport barriers (ITBs) are observed in reversed (negative) shear discharges where diffusivities for electron and ion thermal channels and momentum are reduced. While neutral beam heating can produce ITBs in both electron and ion channels, high harmonic fast wave heating can also produce electron ITBs (e-ITBs) under reversed magnetic shear conditions without momentum input. Interestingly, the location of the e-ITB does not necessarily match that of the ion ITB (i-ITB). The e-ITB location correlates best with the magnetic shear minima location determined by motional Stark effect constrained equilibria, whereas the i-ITB location better correlates with the location of maximum ExB shearing rate. Measured electron temperature gradients in the e-ITB can exceed critical gradients for the onset of electron thermal gradient microinstabilities calculated by linear gyrokinetic codes. A high-k microwave scattering diagnostic shows locally reduced density fluctuations at wave numbers characteristic of electron turbulence for discharges with strongly negative magnetic shear versus weakly negative or positive magnetic shear. Reductions in fluctuation amplitude are found to be correlated with the local value of magnetic shear. These results are consistent with nonlinear gyrokinetic simulations predicting a reduction in electron turbulence under negative magnetic shear conditions despite exceeding critical gradients.X1128sciescopu