In-medium vector meson masses in a Chiral SU(3) model

A significant drop of the vector meson masses in nuclear matter is observed in a chiral SU(3) model due to the effects of the baryon Dirac sea. This is taken into account through the summation of baryonic tadpole diagrams in the relativistic Hartree approximation. The appreciable decrease of the in-medium vector meson masses is due to the vacuum polarisation effects from the nucleon sector and is not observed in the mean field approximation.Comment: 26 pages including 10 figures; the text has been modified for clarit

Note on SLE and logarithmic CFT

It is discussed how stochastic evolutions may be linked to logarithmic conformal field theory. This introduces an extension of the stochastic Loewner evolutions. Based on the existence of a logarithmic null vector in an indecomposable highest-weight module of the Virasoro algebra, the representation theory of the logarithmic conformal field theory is related to entities conserved in mean under the stochastic process.Comment: 10 pages, LaTeX, v2: version to be publishe

Influence of high-dose aprotinin treatment on blood loss and coagulation patterns in open-heart surgery

Intraoperative administration of the proteinase Inhibitor aprotinin causes reduction in blood loss and homologous blood requirement in patients undergoing cardiac surgery. To ascertain the blood-saving effect of aprotinin and to obtain further information about the mode of action, 40 patients undergoing primary myocardial revascularization were randomly assigned to receive either aprotinin or placebo treatment. Aprotinin was given as a bolus of 2 X 105 kallikrein inactivator units (KIU) before surgery followed by a continuous infusion of 5 X 105 KIU/h during surgery. Additionally, 2 X 105 KIU were added to the pump prime. Strict criteria were used to obtain a homogeneous patient selection. Total blood loss was reduced from 1,431 +/- 760 ml in the control group to 738 +/- 411 ml in the aprotinin group (P < 0.05) and the homologous blood requirement from 838 +/- 963 ml to 163 +/- 308 ml (P < 0.05). In the control group, 2.3 +/- 2.2 U of homologous blood or blood products were given, and in the aprotinin group, 0.63 +/- 0.96 U were given (P < 0.05). Twenty-five percent of patients in the control group and 63% in the aprotinin group did not receive banked blood or homologous blood products. The activated clotting time as an indicator of inhibition of the contact phase of coagulation was significantly Increased before heparinization in the aprotinin group (141 +/- 13 s vs. 122 +/- 25 s) and remained significantly Increased until heparin was neutralized after cardiopulmonary bypass (CPB). The concentration of the thrombin-antithrombin III complex was significantly decreased at the end of CPB in the aprotinin group, indicating less thrombin generation in the aprotinin-treated group. The total concentration of the fibrinogen-fibrin split products (FSP) and the split products of the cross-linked fibrin (D-dimers) were also significantly reduced due to attenuated proteolytic activities of thrombin and plasmin. The results of the fibrin plate assay revealed higher fibrinolytic activity during CPB in the control group. The results demonstrate the beneficial effect of high-dose aprotinin treatment on blood loss and homologous blood requirement. This effect can be attributed to the inhibition of the contact phase of coagulation and the consequently reduced thrombotic and fibrionolytic activity during and after CPB

Kaons and antikaons in asymmetric nuclear matter

The properties of kaons and antikaons and their modification in isospin asymmetric nuclear matter are investigated using a chiral SU(3) model. These isospin dependent medium effects are important for asymmetric heavy ion collision experiments. In the present work, the medium modifications of the energies of the kaons and antikaons, within the asymmetric nuclear matter, arise due to the interactions of kaons and antikaons with the nucleons and scalar mesons. The values of the parameters in the model are obtained by fitting the saturation properties of nuclear matter and kaon-nucleon scattering lengths. The pion-nucleon scattering lengths are also calculated within the chiral effective model and compared with earlier results from the literature. The density dependence of the isospin asymmetry is seen to be appreciable for the kaon and antikaon optical potentials. This can be particularly relevant for the future accelerator facility FAIR at GSI, where experiments using neutron rich beams are planned to be used in the study of compressed baryonic matter

Design guidelines for use of adhesives and organic coatings in hybrid microcircuits

A study was conducted to investigate the reliability of organic adhesives in hybrid microcircuits. The objectives were twofold: (1) to identify and investigate problem areas that could result from the use of organic adhesives and (2) to develop evaluation tests to quantify the extent to which these problems occur for commercially available adhesives. Efforts were focused on electrically conductive adhesives. Also, a study was made to evaluate selected organic coatings for contamination protection for hybrid microcircuits

Fractal dimension of domain walls in the Edwards-Anderson spin glass model

We study directly the length of the domain walls (DW) obtained by comparing the ground states of the Edwards-Anderson spin glass model subject to periodic and antiperiodic boundary conditions. For the bimodal and Gaussian bond distributions, we have isolated the DW and have calculated directly its fractal dimension $d_f$. Our results show that, even though in three dimensions $d_f$ is the same for both distributions of bonds, this is clearly not the case for two-dimensional (2D) systems. In addition, contrary to what happens in the case of the 2D Edwards-Anderson spin glass with Gaussian distribution of bonds, we find no evidence that the DW for the bimodal distribution of bonds can be described as a Schramm-Loewner evolution processes.Comment: 6 pages, 5 figures. Accepted for publication in PR

Lipopeptides as dimerization inhibitors of HIV-1 protease

In AIDS therapy, attempts have been made to inhibit the virus-encoded enzymes, e.g, HIV-1 protease, using active site-directed inhibitors. This approach is questionable, however, due to virus mutations and the high toxicity of the drugs, An alternative method to inhibit the dimeric HIV protease is the targeting of the interface region of the protease subunits in order to prevent subunit dimerization and enzyme activity, This approach should be less prone to inactivation by mutation, A list of improved 'dimerization inhibitors' of HIV-1 protease is presented. The main structural features are a short `interface' peptide segment, including non-natural amino acids, and an aliphatic N-terminal blocking group. The high inhibitory power of some of the lipopeptides {[}e.g, palmitoyl-Tyr-Glu-Leu-OH, palmitoyl-Tyr-Glu-(L-thyronine)-OH, palmitoyl-Tyr-Glu-(L-biphenyl-alanine)-OH] with low nanomolar K-i values in the enzyme test suggests that mimetics with good bio-availability can be derived for AIDS therapy

Critical curves in conformally invariant statistical systems

We consider critical curves -- conformally invariant curves that appear at critical points of two-dimensional statistical mechanical systems. We show how to describe these curves in terms of the Coulomb gas formalism of conformal field theory (CFT). We also provide links between this description and the stochastic (Schramm-) Loewner evolution (SLE). The connection appears in the long-time limit of stochastic evolution of various SLE observables related to CFT primary fields. We show how the multifractal spectrum of harmonic measure and other fractal characteristics of critical curves can be obtained.Comment: Published versio