Soliton complexes in dissipative systems: vibrating, shaking and mixed soliton pairs

We show, numerically, that coupled soliton pairs in nonlinear dissipative systems modeled by the cubic-quintic complex Ginzburg-Landau equation can exist in various forms. They can be stationary, or they can pulsate periodically, quasiperiodically, or chaotically, as is the case for single solitons. In particular, we have found various types of vibrating and shaking soliton pairs. Each type is stable in the sense that a given bound state exists in the same form indefinitely. New solutions appear at special values of the equation parameters, thus bifurcating from stationary pairs. We also report the finding of mixed soliton pairs, formed by two different types of single solitons. We present regions of existence of the pair solutions and corresponding bifurcation diagrams

Rapid kinetics of the interaction between daunomycin and drug-sensitive or drug-resistant P388 leukemia cells

AbstractThe initial stages of the interaction of daunomycin (DNM) with drug-sensitive (P388/S) and drug-resistant (P388/100) cells have been defined by a rapid kinetics stopped-flow procedure. The process can be described by two kinetic components. The faster component accounts for rapid occupation of cell surface sites by DNM, as supported by experiments with liposomes with different surface charge. On the other hand, the effect of verapamil in the assays, suggests that the slower component is involved in the transport of the drug into the cells. Our observations are consistent with a loss in the control of the passive permeability to the drugs in the drug-resistant tumor cells

Optical bullets and double bullet complexes in dissipative systems

We show that optical light bullets can coexist with double bullet complexes in nonlinear dissipative systems. Coexistence occurs for a relatively large range of the system parameters, and is associated with either marginal stability or bistable existence of the two dissipative soliton species. In the case of marginal stability, spontaneous transformations of single bullets into double bullet complexes are observed. Among the bistable cases, we show how both clockwise and anticlockwise rotating double bullet complexes can be formed out of the phase-controlled interaction of two single bullets. The internal dynamics of pulsating double bullet complexes, with oscillations in both the spatial separation between the two bullets and the bullet shape in time domain is also detailed

Experimental evidence for soliton explosions

We show, experimentally and numerically, that Ti:sapphire mode-locked lasers can operate in a regime in which they intermittently produce exploding solitons. This happens when the laser operates near a critical point. Explosions happen spontaneously, but external perturbations can trigger them. In stable operation, all explosions have similar features, but are not identical. The characteristics of the explosions depend on the intracavity dispersion

An Embedded-Sensor Approach for Concrete Resistivity Measurement in On-Site Corrosion Monitoring: Cell Constants Determination

[EN] The concrete electrical resistivity is a prominent parameter in structural health monitoring, since, along with corrosion potential, it provides relevant qualitative diagnosis of the reinforcement corrosion. This study proposes a simple expression to reliable determine resistivity from the concrete electrical resistance (R-E) provided by the corrosion sensor of the Integrated Network of Sensors for Smart Corrosion Monitoring (INESSCOM) we have developed. The novelty here is that distinct from common resistivity sensors, the cell constants obtained by the proposed expression are intended to be valid for any sensor implementation scenario. This was ensured by studying most significant geometrical features of the sensor in a wide set of calibration solutions. This embedded-sensor approach is intended to be applicable for R-E measurements obtained both using potential step voltammetry (PSV, used in the INESSCOM sensor for corrosion rate measurement) and alternating current methods. In this regard, we present a simple protocol to reliably determine R-E, and therefore resistivity, from PSV measurements. It consists in adding a very short potentiostatic pulse to the original technique. In this way, we are able to easy monitor resistivity along with corrosion rate through a single sensor, an advantage which is not usual in structural health monitoring.This research was funded by the pre-doctoral scholarship granted to Jose Enrique Ramon Zamora by the Spanish Ministry of Science and Innovation, grant number FPU13/00911. Funding was also provided by the Spanish Ministry of Economy and Competitiveness under the national program for research, development and innovation geared to societal challenges; project number BIA2016-78460-C3-3-R. The research activity reported in this paper has been partially possible thanks to the project Voltammetric Electronic Tongue for Durability Control in Concrete funded by the Universitat Politecnica de Valencia, project number SP20180245.Ramón, JE.; Martínez, I.; Gandía-Romero, JM.; Soto Camino, J. (2021). An Embedded-Sensor Approach for Concrete Resistivity Measurement in On-Site Corrosion Monitoring: Cell Constants Determination. Sensors. 21(7):1-23. https://doi.org/10.3390/s21072481S12321

Dissipative soliton resonances in laser models with parameter management

Dissipative soliton resonance (DSR) is a phenomenon where the energy of a soliton in a dissipative system increases without limit at certain values of the system parameters. We have found that the DSR phenomenon is robust and does not disappear when perturbations are introduced into the model. In particular, parameter management is benign to DSR: the resonance property remains intact even when a pulse experiences periodic changes of system parameters in a laser cavity. We also show that high energy pulses emerging from a laser cavity can be compressed to shorter durations with the help of linear dispersive devices.The work was supported by the Australian Research Council (Discovery Project scheme DP0663216). J. M. Soto-Crespo acknowledges support from the Ministerio de Educación y Cultura under contract FIS2006-03376

Transformations of continuously self-focusing and continuously self-defocusing dissipative solitons

Dissipative media admit the existence of two types of stationary self-organized beams: continuously self-focused and continuously selfdefocused. Each beam is stable inside of a certain region of its existence. Beyond these two regions, beams loose their stability, and new dynamical behaviors appear. We present several types of instabilities related to each beam configuration and give examples of beam dynamics in the areas adjacent to the two regions. We observed that, in one case beams loose the radial symmetry while in the other one the radial symmetry is conserved during complicated beam transformations

Dissipative ring solitons with vorticity

We study dissipative ring solitons with vorticity in the frame of the (2+1)-dimensional cubic-quintic complex Ginzburg-Landau equation. In dissipative media, radially symmetric ring structures with any vorticity m can be stable in a finite range of parameters. Beyond the region of stability, the solitons lose the radial symmetry but may remain stable, keeping the same value of the topological charge. We have found bifurcations into solitons with n-fold bending symmetry, with n independent on m. Solitons without circular symmetry can also display (m + 1)-fold modulation behaviour. A sequence of bifurcations can transform the ring soliton into a pulsating or chaotic state which keeps the same value of the topological charge as the original ring

Leishmania infantum HSP70-II null mutant as candidate vaccine against leishmaniasis: a preliminary evaluation

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis is the most severe form of leishmaniasis and no effective vaccine exists. The use of live attenuated vaccines is emerging as a promising vaccination strategy.</p> <p>Results</p> <p>In this study, we tested the ability of a <it>Leishmania infantum </it>deletion mutant, lacking both <it>HSP70-II </it>alleles (ΔHSP70-II), to provide protection against <it>Leishmania </it>infection in the <it>L. major</it>-BALB/c infection model. Administration of the mutant line by either intraperitoneal, intravenous or subcutaneous route invariably leads to the production of high levels of NO and the development in mice of type 1 immune responses, as determined by analysis of anti-<it>Leishmania </it>IgG subclasses. In addition, we have shown that ΔHSP70-II would be a safe live vaccine as immunodeficient SCID mice, and hamsters (<it>Mesocricetus auratus</it>), infected with mutant parasites did not develop any sign of pathology.</p> <p>Conclusions</p> <p>The results suggest that the ΔHSP70-II mutant is a promising and safe vaccine, but further studies in more appropriate animal models (hamsters and dogs) are needed to appraise whether this attenuate mutant would be useful as vaccine against visceral leishmaniasis.</p

Proline derivatives incorporating hydrophobic long-chain derived from natural and synthetic fatty acids

The α-hydrophobic long chain-α-amino esters are prepared by α-hydroxylation of a series of fatty acid esters [derived from oleic acid (OA), linoleic acid (LA), arachidonic acid (ARA) and docosahexaenoic acid (DHA)] followed by Mitsunobu reaction and hydrazinolysis of the phthalimide. These amino esters are mixed with aldehydes and electrophilic alkenes to give very good chemical yields and diastereoselectivities of prolinate derivatives incorporating a hydrophobic long chain at the α-position. This multicomponent 1,3-dipolar cycloaddition (1,3-DC) takes place at room temperature. The synthesis of the homologue hydrophobic chain of OA is performed by its oxidation to aldehyde/racemic N-tert-butylsulfinyl imine/Neff reaction. Final 1,3-DC with benzaldehyde and N-methylmaleimide affords homologue prolinate derivative in good yield.We gratefully acknowledge financial support from the Spanish Ministerio Ministerio de Ciencia, Innovación y Universidades (projects CTQ2013-43446-P and CTQ2014-51912-REDC), the Spanish Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER, EU) (projects CTQ2016-76782-P and CTQ2016-81797-REDC), the Generalitat Valenciana (PROMETEOII/2014/017), Medalchemy, S. L. and the University of Alicante. E. S.-M. thanks Medalchemy, S. L./UA for a predoctoral fellowship