THE RAMIFICATION PATTERN OF PORTAL VEIN IN LEFT LOBE OF HUMAN LIVER STUDIED BY CORROSION CAST METHOD.

INTRODUCTION: The aim of the study was to know the intrahepatic ramication pattern of portal vein in left lobe of liver & its variations. METHODS: 25 human fresh livers were obtained after autopsy and studied by corrosion cast method. Polymeric granules of butyl butyrate were dissolved in acetone and 20% homogenous solution was made. Solution was injected into portal vein and the injected liver was placed in 10 % formal saline for 24 hours at room temperature (20°C) for polymerization of infused butyl butyrate solution. Maceration of liver tissue achieved by whole-organ immersion in 1.8 N KOH solution at 68°C for 24 hrs. Each cast thus obtained was preserved in glycerin and details were studied. RESULTS: The length of the transverse part of Left portal vein (LPV) varies from 1.5 -3.7 cm (2.6 cm) while the length of umbilical part of LPV varied from 0.5 – 1.5 cm. (1.1cm.) and total length of LPV varies from 2.0 cm.-4.8cm.(3.7cm). Ramication of Left Portal Vein was described on the basis of its umbilical part. Two type of pattern observed Type I (Umbilical Part Turned Inferiorly) 60 % cases & Type II (Umbilical Part Turned Superiorly). For segment II - Cranio- lateral (CAL) branch originated from the convexity of the curved portion of the umbilical part 84 % cases while in 16 % it has originated from the transverse part of the LPV. Segment III- Caudo- lateral branch (CRL) originated from the convexity of the curved portion of the umbilical part of LPV in all the cases. Segment IV- From the concavity, Inferio – medial branch ran downward & medially while superior- medial branch ran superiorly & medially to supply the lower & upper part of segment IV respectively. The both superio- medial & inferio-medial branches were present in 13 of 25 cases (52 %), while only superior -medial branches were present in 16 of 25 cases (64 %) cases & only inferio-medial 21 of 25 cases (84%) in cases. In 5 of 25 cases (20 %), a common trunk has originated from the concavity of curved portion of the umbilical part then it divided in to superior-medial & inferio-medial branches to supply the segment IV. The number of portal branches to the caudate lobe (segment I) varied from 1 to 4 branches: most commonly from LPV (52 %), then portal vein (16%) & then right portal vein12% cases. At least one of these branches was always originated from LPV (100%). The number of the branches to supply the caudate lode was 2 as it observed in 56 %, while 3 braches in 16 % cases & 4 branches were present in only 8% of the cases. The ndings of present CONCLUSIONS: study on hepatic vasculature have immense importance in the eld of hepato-biliary surgeries.

Geometric momentum and angular momentum for charge-monopole system

For a charge-monopole pair, we have another definition of the orbital angular momentum, and the transverse part of the momentum including the vector potential turns out to be the so-called geometric momentum that is under intensive study recently. For the charge on the spherical surface with the monopole at the origin, the commutation relations between all components of both the geometric momentum and the orbital angular momentum satisfy the so(3,[Formula: see text]1) algebra. With construction of the geometrically infinitesimal displacement operator based on the geometric momentum, the so(3,[Formula: see text]1) algebra implies the Aharonov–Bohm phase shift. The related problems such as charge and flux quantization are also addressed.

Influence of Core Suture Geometry on Tendon Deformation and Gap Formation in Porcine Flexor Tendons

The effects of core suture geometry on the mechanics of failure in flexor tendon surgery are investigated. Forty porcine flexor tendons were repaired using a Kessler; a Kessler-Pennington; a double Kessler; a continuous Kessler; and a cruciate repair. At maximum breaking strength, the cruciate repair gapped more then the double Kessler (12.8 mm vs 9.1 mm), but the double Kessler was less strong (37N vs 45 N). Transverse narrowing was 22% and 24% for the Kessler and the Kessler-Pennington, 11% for the double Kessler, and 0% for the continuous Kessler and the cruciate repair. Kessler-type sutures failed by suture breakage and the cruciate repair by pull-out. Under load, the transverse part of the Kessler sutures narrows, allowing longitudinal parts to lengthen, leading to gapping. The double Kessler shortened transverse segment decreases gapping. Eliminating a transverse component (the cruciate repair) decreased gapping, but the cruciate failed at higher loads by suture pull-out.

PHONON EXCESS HEATING IN ELECTRONIC RELAXATION THEORY IN QUANTUM DOTS

When the usual operator of the Fröhlich's coupling between electrons and longitudinal optical phonons of semiconductor single quantum dot is used to calculate electronic energy relaxation, a permanent phonon generation in quantum dot is obtained, leading to an artificial effect of permanent heating up of the lattice. The mechanism of the phonon heating is identified here with the influence of the transverse part of the interaction operator. This part is responsible first of all for a tendency to build the polaronic well of an electron in a quantum dot. The effect of overheating is shown to be possibly eliminated to a considerable extent upon removing the transverse part of the interaction with the help of the Lang–Firsov canonical transformation and upon modifying accordingly the longitudinal part of the coupling. The resulting electronic relaxation and optical phonon generation is demonstrated numerically in a relatively simple approximation to electron and phonon self-energy, in which the model of quantum dot is reduced to an electron coupled to a single-LO-phonon mode. It is interesting to see that the removal of the phonon overheating based on the application of the Lang–Firsov canonical transformation has a rather small influence on electronic characteristics calculated with electronic transport equations. In this sense, the long-time limit properties of the electronic subsystem, like the electronic up-conversion and incomplete depopulation effect, calculated earlier, remain nearly untouched.

TRANSVERSE WARD–TAKAHASHI RELATION FOR THE FERMION–BOSON VERTEX TO ONE-LOOP ORDER

In this paper, the transverse Ward–Takahashi relation for the fermion–boson vertex in momentum space is derived in four-dimensional Abelian gauge theory. We show that, by a formal derivation, the transverse Ward–Takahashi relation to one-loop order is satisfied. We also calculate the transverse Ward–Takahashi relation to one-loop order in an arbitrary covariant gauge in the case of massless fermions and find that the result is exactly the same as we obtain in terms of the one-loop fermion–boson vertex calculated in perturbation theory by using Feynman rules. This provides an approach to determine the transverse part of the vertex.

ON THE INTERACTION BETWEEN THERMALIZED NEUTRINOS AND COSMOLOGICAL GRAVITATIONAL WAVES ABOVE THE ELECTROWEAK UNIFICATION SCALE

We investigate the interaction between the cosmological relic neutrinos, and primordial gravitational waves entering the horizon before the electroweak phase transition, corresponding to observable frequencies today ν0≳10-5 Hz . We give an analytic formula for the traceless transverse part of the anisotropic stress tensor, due to weakly interacting neutrinos, and derive an integro-differential equation describing the propagation of cosmological gravitational waves at these conditions. We find that this leads to a decrease of the wave intensity in the frequency region accessible to the LISA space interferometer, that is at the present the most promising way to obtain a direct detection of a cosmological gravitational wave. The absorbed intensity does not depend neither on the perturbation wavelength, nor on the details of neutrino interactions, and is affected only by the neutrino fraction fν. The transmitted intensity amounts to 88% for the standard value fν=0.40523. An approximate formula for non-standard values of fν is given.