Diffusion approximation for equilibrium Kawasaki dynamics in continuum

A Kawasaki dynamics in continuum is a dynamics of an infinite system of interacting particles in $\mathbb R^d$ which randomly hop over the space. In this paper, we deal with an equilibrium Kawasaki dynamics which has a Gibbs measure $\mu$ as invariant measure. We study a diffusive limit of such a dynamics, derived through a scaling of both the jump rate and time. Under weak assumptions on the potential of pair interaction, $\phi$, (in particular, admitting a singularity of $\phi$ at zero), we prove that, on a set of smooth local functions, the generator of the scaled dynamics converges to the generator of the gradient stochastic dynamics. If the set on which the generators converge is a core for the diffusion generator, the latter result implies the weak convergence of finite-dimensional distributions of the corresponding equilibrium processes. In particular, if the potential $\phi$ is from $C_{\mathrm b}^3(\mathbb R^d)$ and sufficiently quickly converges to zero at infinity, we conclude the convergence of the processes from a result in [Choi {\it et al.}, J. Math. Phys. 39 (1998) 6509--6536]

Toxicology and efficacy of tumor-targeting Salmonella typhimurium A1-R compared to VNP 20009 in a syngeneic mouse tumor model in immunocompetent mice.

Salmonella typhimurium A1-R (S. typhimurium A1-R) attenuated by leu and arg auxotrophy has been shown to target multiple types of cancer in mouse models. In the present study, toxicologic and biodistribution studies of tumor-targeting S. typhimurium A1-R and S. typhimurium VNP20009 (VNP 20009) were performed in a syngeneic tumor model growing in immunocompetent BALB/c mice. Single or multiple doses of S. typhimurium A1-R of 2.5 × 105 and 5 × 105 were tolerated. A single dose of 1 × 106 resulted in mouse death. S. typhimurium A1-R (5 × 105 CFU) was eliminated from the circulation, liver and spleen approximately 3-5 days after bacterial administration via the tail vein, but remained in the tumor in high amounts. S. typhimurium A1-R was cleared from other organs much more rapidly. S. typhimurium A1-R and VNP 20009 toxicity to the spleen and liver was minimal. S. typhimurium A1-R showed higher selective targeting to the necrotic areas of the tumors than VNP20009. S. typhimurium A1-R inhibited the growth of CT26 colon carcinoma to a greater extent at the same dose of VNP20009. In conclusion, we have determined a safe dose and schedule of S. typhimurium A1-R administration in BALB/c mice, which is also efficacious against tumor growth. The results of the present report indicate similar toxicity of S. typhimurium A1-R and VNP20009, but greater antitumor efficacy of S. typhimurium A1-R in an immunocompetent animal. Since VNP2009 has already proven safe in a Phase I clinical trial, the present results indicate the high clinical potential of S. typhimurium A1-R

Long-Range Correlations and the Momentum Distribution in Nuclei

The influence of correlations on the momentum distribution of nucleons in nuclei is evaluated starting from a realistic nucleon-nucleon interaction. The calculations are performed directly for the finite nucleus \,^{16}O making use of the Green's function approach. The emphasis is focused on the correlations induced by the excitation modes at low energies described within a model-space of shell-model configurations including states up to the sdg shell. Our analysis demonstrates that these long-range correlations do not produce any significant enhancement of the momentum distribution at high missing momenta and low missing energies. This is in agreement with high resolution $(e,e'p)$ experiments for this nucleus. We also try to simulate the corresponding effects in large nuclei by quenching the energy-spacing between single-particle orbits. This yields a sizable enhancement of the spectral function at large momenta and small energy. Such behavior could explain the deviation of the momentum distribution from the mean field prediction, which has been observed in $(e,e'p)$ experiments on heavy nuclei like $^{208}$Pb

Synthesis of cyclopropyl-substituted furans by Brønsted acid promoted cascade reactions

Chloroacetic acid promotes an efficient and diastereoselective intramolecular cascade reaction of electron-deficient ynenones to deliver products featuring a 2,3,5-trisubstituted furan bearing a fused cyclopropyl substituent at the 5-position. Synthetically relevant polycyclic building blocks featuring rings of various sizes and heteroatoms have been synthesized in high yield using this mild acid-catalyzed reaction

Tight Bell inequalities with no quantum violation from qubit unextendible product bases

We investigate the relation between unextendible product bases (UPB) and Bell inequalities found recently in [R. Augusiak et al., Phys. Rev. Lett. 107, 070401 (2011)]. We first review the procedure introduced there that associates to any set of mutually orthogonal product vectors in a many-qubit Hilbert space a Bell inequality. We then show that if a set of mutually orthogonal product vectors can be completed to a full basis, then the associated Bell inequality is trivial, in the sense of not being violated by any nonsignalling correlations. This implies that the relevant Bell inequalities that arise from the construction all come from UPBs, which adds additional weight to the significance of UPBs for Bell inequalities. Then, we provide new examples of tight Bell inequalities with no quantum violation constructed from UPBs in this way. Finally, it is proven that the Bell inequalities with no quantum violation introduced recently in [M. Almeida et al., Phys. Rev. Lett. 104, 230404 (2010)] are tight for any odd number of parties.Comment: 14 pages, 1 figure, some minor improvement

Correlations and the Cross Section of Exclusive (e,e′pe,e'p) Reactions for 16^{16}O

The reduced cross section for exclusive ($e,e'p$) reactions has been studied in DWIA for the example of the nucleus $^{16}$O using a spectral function containing effects of correlations. The spectral function is evaluated directly for the finite nucleus starting from a realistic nucleon-nucleon interaction within the framework of the Green's function approach. The emphasis is focused on the correlations induced by excitation modes at low energies described within a model-space of shell-model configurations including states up to the $sdg$ shell. Cross sections for the $p$-wave quasi-hole transitions at low missing energies are presented and compared with the most recent experimental data. In the case of the so-called perpendicular kinematics the reduced cross section derived in DWIA shows an enhancement at high missing momenta as compared to the PWIA result. Furthermore the cross sections for the $s$- and $d$-wave quasi-hole transitions are presented and compared to available data at low missing momenta. Also in these cases, which cannot be described in a model without correlations, a good agreement with the experiment is obtained.Comment: 12 pages, LaTeX, 4 figures include

Description of nuclear systems within the relativistic Hartree-Fock method with zero range self-interactions of the scalar field

An exact method is suggested to treat the nonlinear self-interactions (NLSI) in the relativistic Hartree-Fock (RHF) approach for nuclear systems. We consider here the NLSI constructed from the relativistic scalar nucleon densities and including products of six and eight fermion fields. This type of NLSI corresponds to the zero range limit of the standard cubic and quartic self-interactions of the scalar field. The method to treat the NLSI uses the Fierz transformation, which enables one to express the exchange (Fock) components in terms of the direct (Hartree) ones. The method is applied to nuclear matter and finite nuclei. It is shown that, in the RHF formalism, the NLSI, which are explicitly isovector-independent, generate scalar, vector and tensor nucleon self-energies strongly density-dependent. This strong isovector structure of the self-energies is due to the exchange terms of the RHF method. Calculations are carried out with a parametrization containing five free parameters. The model allows a description of both types of systems compatible with experimental data.Comment: 23 pages, 14 figures (v2: major quantitative changes

Kidney Transplantation Group of the Spanish Society of Nephrology

Document publicat també en castellàThe Board of Directors of the Spanish Society of Nephrology (S.E.N.) approved at its ordinary meeting of 18 December 2012 the creation of a Transplantation Working Group (SENTRA). In accordance with the Regulations of the S.E.N. Working Groups, in promoting the establishment of a working group, four priority aspects must be addressed..