Phase transition of interacting disordered bosons in one dimension

Interacting bosons generically form a superfluid state. In the presence of disorder it can get converted into a compressible Bose glass state. Here we study such transition in one dimension at moderate interaction using bosonization and renormalization group techniques. We derive the two-loop scaling equations and discuss the phase diagram. We find that the correlation functions at the transition are characterized by universal exponents in a finite region around the fixed point.Comment: five pages and two pages and one figur

Distribution of velocities and acceleration for a particle in Brownian correlated disorder: inertial case

We study the motion of an elastic object driven in a disordered environment in presence of both dissipation and inertia. We consider random forces with the statistics of random walks and reduce the problem to a single degree of freedom. It is the extension of the mean field ABBM model in presence of an inertial mass m. While the ABBM model can be solved exactly, its extension to inertia exhibits complicated history dependence due to oscillations and backward motion. The characteristic scales for avalanche motion are studied from numerics and qualitative arguments. To make analytical progress we consider two variants which coincide with the original model whenever the particle moves only forward. Using a combination of analytical and numerical methods together with simulations, we characterize the distributions of instantaneous acceleration and velocity, and compare them in these three models. We show that for large driving velocity, all three models share the same large-deviation function for positive velocities, which is obtained analytically for small and large m, as well as for m =6/25. The effect of small additional thermal and quantum fluctuations can be treated within an approximate method.Comment: 42 page

ROS-inducing potential, influence of different porogens and in vitro degradation of poly (D,L-lactide-co-glycolide)-based material

Porous, poly(D, L-lactide-co-glycolide) (PLGA) materials were prepared by physicochemical solvent/non-solvent method with polyvinyl pyrrolidone (PVP) as a stabilizer and with silicone oil, paraffin, hydrogen peroxide or sodium chloride as a porogen. The obtained PLGA particles without porogens are non-agglomerated, uniform and with particle size on the submicron scale. The formation of intracellular reactive oxygen species (ROS) was measured spectrophotometrically using a fluorescent probe, 2,7-dichlorofluorescein diacetate (DCFH-DA) and it is shown that PLGA nanospheres are not inducers of intracellular formation. Porous PLGA scaffolds obtained in the experiment with sodium chloride as porogen and water as solvent of the porogen had apparently uniform pore morphology with spheroidal pore in shape and well controlled three-dimensional interconnected network. PLGA scaffolds are highly porous with similar porosity values. The degradation of PLGA nanoparticles and PLGA porous materials were studied in phosphate buffered saline as a degradation medium. The samples were characterized by Infrared Spectroscopy (IR), X-ray difractometry, Zeta potential measurements, Scanning Electron Microscopy (SEM) and Ultraviolet Spectroscopy (UV)

Carrier drift velocity and edge magnetoplasmons in graphene

We investigate electron dynamics at the graphene edge by studying the propagation of collective edge magnetoplasmon (EMP) excitations. By timing the travel of narrow wave-packets on picosecond time scales around exfoliated samples, we find chiral propagation with low attenuation at a velocity which is quantized on Hall plateaus. We extract the carrier drift contribution from the EMP propagation and find it to be slightly less than the Fermi velocity, as expected for an abrupt edge. We also extract the characteristic length for Coulomb interaction at the edge and find it to be smaller than for soft, depletion edge systems.Comment: 5 pages, 3 figures of main text and 6 pages, 6 figures of supplemental materia

Oxidative Activity of Human Polymorphonuclear Leukocytes Stimulated by the Long-Chain Phosphatidic Acids

Summary It has already been suggested that phosphatidic acids (PAs) play an important role in the regulation of signaling pathways involved in the production of reactive oxygen species (ROS) by human polymorphonuclear leukocytes (PMNs). The present study was performed to elucidate the effects of extracellularly added PAs -1,2-distearoyl-(DSPA) and 1-stearoyl-2-arachidonoyl-sn-glycero-phosphate (SAPA) -on the ROS production and on the elastase release by human PMNs. ROS production was monitored by luminol-amplified chemiluminescence and the elastase activity was measured in the supernatant of the PA-stimulated human PMNs by colorimetric assay. Obtained effects were compared with those of cells stimulated by either a chemotactic tripeptide, phorbol ester or calcium ionophore. Our results show that long-chain PAs at concentrations higher than 3 × 10 -5 mol/l stimulate the ROS production by human PMNs, whereas they were ineffective in promoting the elastase release. The chemiluminescence pattern of the SAPA-stimulated cells exhibited a biphasic curve, whereas cell stimulation with DSPA resulted in a monophasic chemiluminescence curve. Stimulation of the ROS production by PAs in dependence of the fatty acid composition required the activity of protein kinases

A Declarative Framework for Specifying and Enforcing Purpose-aware Policies

Purpose is crucial for privacy protection as it makes users confident that their personal data are processed as intended. Available proposals for the specification and enforcement of purpose-aware policies are unsatisfactory for their ambiguous semantics of purposes and/or lack of support to the run-time enforcement of policies. In this paper, we propose a declarative framework based on a first-order temporal logic that allows us to give a precise semantics to purpose-aware policies and to reuse algorithms for the design of a run-time monitor enforcing purpose-aware policies. We also show the complexity of the generation and use of the monitor which, to the best of our knowledge, is the first such a result in literature on purpose-aware policies.Comment: Extended version of the paper accepted at the 11th International Workshop on Security and Trust Management (STM 2015

On a computer-aided approach to the computation of Abelian integrals

An accurate method to compute enclosures of Abelian integrals is developed. This allows for an accurate description of the phase portraits of planar polynomial systems that are perturbations of Hamiltonian systems. As an example, it is applied to the study of bifurcations of limit cycles arising from a cubic perturbation of an elliptic Hamiltonian of degree four

Nucleon pairing in μ- capture by 40Ca

Spectra of energetic protons above 35 MeV have been measured following negative muon capture from rest in Ca. The spectrum extends to the kinematic limit near 93 MeV, with a branching ratio of (2.3±0.3)×10-4 per capture above 40 MeV. Nuclear cascade calculations of the proton and neutron spectra in this energy region are presented and are consistent with the measured proton spectrum when capture on correlated pp and np pairs in the nucleus is included. The ratio of capture on np to pp pairs is 6.7±1.6, which is consistent with results from pion capture

Spectroscopic and quantum chemical elucidation of newly synthesized 1-aryl-3-methyl-3-phenylpyrrolidine-2,5-diones as potential anticonvulsant agents

Novel succinimide derivatives were synthesized from 3-methyl-3-phenylsuccinic acid and substituted anilines under solvent-free conditions by using microwave irradiation. All obtained compounds were characterized by ultraviolet (UV), Fourier-transform infrared (FT-IR), H-1 and C-13 nuclear magnetic resonance (NMR) spectroscopy as well as by elemental analysis. The influence of the substituent electronic effects on spectroscopic data was analyzed by applying the Hammett equation. Moreover, a detailed interpretation and comparison of experimentally obtained and theoretically calculated FT-IR, UV and NMR spectra was performed. Density functional theory (DFT) calculated data of the investigated succinimides were obtained and analyzed in order to determine their structural, spectroscopic and electronic properties. Furthermore, ADMET factor profiling and in-silico prediction of potential biological activities of novel succinimide derivatives have been performed

Chemically heterogeneous carbon dots enhanced cholesterol detection by MALDI TOF mass spectrometry

A binary system composed of carbon dots (CDs) and N-doped CDs (N-CDs) embedded in an organic matrix was used for the analysis of cholesterol by MALDI (matrix-assisted laser desorption and ionization time of-flight) mass spectrometry, as a model for detection of small, biologically relevant molecules. The results showed that both CDs are sensitive to the cholesterol and can be used either alone or in a binary system with 2,5-dihydroxybenzoic acid (DHB) to enhance the detection process. It was found that both COOH and NH2 groups on CDs surface contributed to the enhancement in the cholesterol detection by MALDI mass spectrometry in the presence of inorganic cations. Nevertheless, in the presence of NaCl, N-CDs led to a better reproducibility of results. It was due to the coexistence of positive and negative charge on N-CDs surface that led to a homogeneous analyte/substrate distribution, which is an important detection parameter. The enhancing effect of carbon dots was linked to a negative Gibbs energy of the complex formation between CDs, Na+ , cholesterol and DHB, and it was supported by theoretical calcula tions. Moreover, upon the addition of CDs/N-CDs, such features as a low ionization potential, vertical excitation, dipole moment and oscillator strength positively affected the cholesterol detection by MALDI in the presence of Na+.info:eu-repo/semantics/publishedVersio