Thermostatistical description of small systems in nonequilibrium conditions: Energy conversion and harvesting

Hysteresis cycles are very important features of energy conversion and harvesting devices, such as batteries. The efficiency of these may be strongly affected by the physical size of the system. Here, we show that in systems which are small enough, the existence of physical boundaries which produce nonhomogeneities of the interaction potential gives rise to inflections and barriers in the associated free energy. This in turn brings on irreversible processes which can be triggered under suitable external conditions imposed by a heat bath. As an example, by controlling the temperature, the state of a small system may be impelled to oscillate between two different structural configurations or aggregation states avoiding equilibrium coexistence and therefore dissipating energy. This cyclical behavior associated with a hysteresis cycle may be prototypical of energy conversion, storage, or generating nanodevices, as exemplified by Li-ion insertion batteries.

Diffusion in stationary flow from mesoscopic nonequilibrium thermodynamics

We analyze the diffusion of a Brownian particle in a fluid under stationary flow. By using the scheme of nonequilibrium thermodynamics in phase space, we obtain the Fokker-Planck equation that is compared with others derived from the kinetic theory and projector operator techniques. This equation exhibits violation of the fluctuation-dissipation theorem. By implementing the hydrodynamic regime described by the first moments of the nonequilibrium distribution, we find relaxation equations for the diffusion current and pressure tensor, allowing us to arrive at a complete description of the system in the inertial and diffusion regimes. The simplicity and generality of the method we propose makes it applicable to more complex situations, often encountered in problems of soft-condensed matter, in which not only one but more degrees of freedom are coupled to a nonequilibrium bath.

Reaction-diffusion lattice gas: Theory and computer results

We report on the study of nonequilibrium ordering in the reaction-diffusion lattice gas. It is a kinetic model that relaxes towards steady states under the simultaneous competition of a thermally activated creation-annihilation $(reaction$) process at temperature T, and a diffusion process driven by a heat bath at temperature T?T. The phase diagram as one varies T and T, the system dimension d, the relative priori probabilities for the two processes, and their dynamical rates is investigated. We compare mean-field theory, new Monte Carlo data, and known exact results for some limiting cases. In particular, no evidence of Landau critical behavior is found numerically when d=2 for Metropolis rates but Onsager critical points and a variety of first-order phase transitions.

Oral pathogens in duwl's: risk of infection and strategies for their control

Water lines are an important source of potentíal contamination. Every dental unit is equipped with small-bore flexible plastic tubing to bring water to different hand pieces, such as the air/water syringe, the ultrasonic scaler or the high-speed hand piece. Most dental units are connected directly to municipal distribution systems for potable water and chlorinated or not, this water contains diverse...

Dose and time-dependent selective neurotoxicity induced by mephedrone in mice.

Mephedrone is a drug of abuse marketed as 'bath salts'. There are discrepancies concerning its long-term effects. We have investigated the neurotoxicity of mephedrone in mice following different exposition schedules. Schedule 1: four doses of 50 mg/kg. Schedule 2: four doses of 25 mg/kg. Schedule 3: three daily doses of 25 mg/kg, for two consecutive days. All schedules induced, in some animals, an aggressive behavior and hyperthermia as well as a decrease in weight gain. Mephedrone (schedule 1) induced dopaminergic and serotoninergic neurotoxicity that persisted 7 days after exposition. At a lower dose (schedule 2) only a transient dopaminergic injury was found. In the weekend consumption pattern (schedule 3), mephedrone induced dopamine and serotonin transporter loss that was accompanied by a decrease in tyrosine hydroxylase and tryptophan hydroxylase 2 expression one week after exposition. Also, mephedrone induced a depressive-like behavior, as well as a reduction in striatal D2 density, suggesting higher susceptibility to addictive drugs. In cultured cortical neurons, mephedrone induced a concentration-dependent cytotoxic effect. Using repeated doses for 2 days in an elevated ambient temperature we evidenced a loss of frontal cortex dopaminergic and hippocampal serotoninergic neuronal markers that suggest injuries at nerve endings.

ZnO nanorods for efficient third harmonic UV generation.

ZnO nanorods grown by both high temperature vapour phase transport and low temperature chemical bath deposition are very promising sources for UV third harmonic generation. Material grown by both methods show comparable efficiencies, in both cases an order of magnitude higher than surface third harmonic generation at the quartz-air interface of a bare quartz substrate. This result is in stark contrast to the linear optical properties of ZnO nanorods grown by these two methods, which show vastly different PL efficiencies. The third harmonic generated signal is analysed using intensity dependent measurements and interferometric frequency resolved optical gating, allowing extraction of the laser pulse parameters. The comparable levels of efficiency of ZnO grown by these very different methods as sources for third harmonic UV generation provides a broad suite of possible growth methods to suit various substrates, coverage and scalability requirements. Potential application areas range from interferometric frequency resolved optical gating characterization of few cycle fs pulses to single cell UV irradiation for biophysical studies.

Dose and time-dependent selective neurotoxicity induced by mephedrone in mice.

Mephedrone is a drug of abuse marketed as 'bath salts'. There are discrepancies concerning its long-term effects. We have investigated the neurotoxicity of mephedrone in mice following different exposition schedules. Schedule 1: four doses of 50 mg/kg. Schedule 2: four doses of 25 mg/kg. Schedule 3: three daily doses of 25 mg/kg, for two consecutive days. All schedules induced, in some animals, an aggressive behavior and hyperthermia as well as a decrease in weight gain. Mephedrone (schedule 1) induced dopaminergic and serotoninergic neurotoxicity that persisted 7 days after exposition. At a lower dose (schedule 2) only a transient dopaminergic injury was found. In the weekend consumption pattern (schedule 3), mephedrone induced dopamine and serotonin transporter loss that was accompanied by a decrease in tyrosine hydroxylase and tryptophan hydroxylase 2 expression one week after exposition. Also, mephedrone induced a depressive-like behavior, as well as a reduction in striatal D2 density, suggesting higher susceptibility to addictive drugs. In cultured cortical neurons, mephedrone induced a concentration-dependent cytotoxic effect. Using repeated doses for 2 days in an elevated ambient temperature we evidenced a loss of frontal cortex dopaminergic and hippocampal serotoninergic neuronal markers that suggest injuries at nerve endings.

Repeated doses of methylone, a new drug of abuse, induce changes in serotonin and dopamine systems in the mouse

Rationale Methylone, a new drug of abuse sold as"bath salts' has similar effects to ecstasy or cocaine. Objective We have investigated changes in dopaminergic and serotoninergic markers, indicative of neuronal damage, induced by methylone in the frontal cortex, hippocampus and striatum of mice and according two different treatment schedules. Methods Methylone was given subcutaneously to male Swiss CD1 mice and at an ambient temperature of 26ºC. Treatment A: three doses of 25 mg/Kg at 3.5 h interval between doses for two consecutive days. Treatment B: four doses of 25 mg/Kg at 3 h interval in one day. Results Repeated methylone administration induced hyperthermia and a significant loss in body weight. Following treatment A, methylone induced transient dopaminergic (frontal cortex) and serotoninergic (hippocampus) impairment. Following treatment B, transient dopaminergic (frontal cortex) and serotonergic (frontal cortex and hippocampus) changes 7 days after treatment were found. We found evidence of astrogliosis in the CA1 and the dentate gyrus of the hippocampus following treatment B. The animals also showed an increase in immobility time in the forced swim test, pointing to a depressive-like behavior. In cultured cortical neurons, methylone (for 24 and 48 h) did not induce a remarkable cytotoxic effect. Conclusions The neural effects of methylone differ depending upon the treatment schedule. Neurochemical changes elicited by methylone are apparent when administered at an elevated ambient temperature, four times per day at 3 h intervals, which is in accordance with its short half-life.

Verifique sus conocimientos sobre ecografía

La presente entrega de la serie de Nursing sobre las pruebas complementarias está dedicada a la ecografía. La ecografía está ampliamente difundida como exploración de diagnóstico por la imagen, se utiliza en multitud de procedimientos para diagnóstico inicial y también como apoyo en localizaciones prequirúrgicas, punciones y drenajes. La ecografía es una técnica sencilla, mínimamente invasiva y con gran capacidad diagnóstica. Estas características, junto con su coste reducido en comparación con otras modalidades diagnósticas, han contribuido a su amplia implantación en muy diversos procesos asistenciales. Las exploraciones, dependiendo del tipo de estructura a visualizar y de su objetivo, pueden variar en cuanto a la preparación, la ejecución y el post procedimiento, como se explica en estas páginas. Para llevar a cabo la técnica de manera rápida y eficaz, es básica una preparación adecuada y suministrar información que proporcione al paciente las instrucciones que facilitarán su colaboración. Desde este punto de vista, el profesional de enfermería debe conocer las características del procedimiento ecográfico concreto y ser capaz de informar sobre ellas al paciente. La ecografía la realiza el médico especialista en radiología, aunque en algunos casos y cada vez de manera más habitual, la pueden realizar otros profesionales sanitarios con formación específica a tal efecto.

Verifique sus conocimientos sobre ecografía

La presente entrega de la serie de Nursing sobre las pruebas complementarias está dedicada a la ecografía. La ecografía está ampliamente difundida como exploración de diagnóstico por la imagen, se utiliza en multitud de procedimientos para diagnóstico inicial y también como apoyo en localizaciones prequirúrgicas, punciones y drenajes. La ecografía es una técnica sencilla, mínimamente invasiva y con gran capacidad diagnóstica. Estas características, junto con su coste reducido en comparación con otras modalidades diagnósticas, han contribuido a su amplia implantación en muy diversos procesos asistenciales. Las exploraciones, dependiendo del tipo de estructura a visualizar y de su objetivo, pueden variar en cuanto a la preparación, la ejecución y el post procedimiento, como se explica en estas páginas. Para llevar a cabo la técnica de manera rápida y eficaz, es básica una preparación adecuada y suministrar información que proporcione al paciente las instrucciones que facilitarán su colaboración. Desde este punto de vista, el profesional de enfermería debe conocer las características del procedimiento ecográfico concreto y ser capaz de informar sobre ellas al paciente. La ecografía la realiza el médico especialista en radiología, aunque en algunos casos y cada vez de manera más habitual, la pueden realizar otros profesionales sanitarios con formación específica a tal efecto.

Effect of tow-drop gaps on the damage resistance and tolerance of Variable-Stiffness Panels

This paper presents an experimental study of the effects of tow-drop gaps in Variable Stiffness Panels under drop-weight impact events. Two different configurations, with and without ply-staggering, have been manufactured by Automated Fibre Placement and compared with their baseline counterpart without defects. For the study of damage resistance, three levels of low velocity impact energy are generated with a drop-weight tower. The damage area is analysed by means of ultrasonic inspection. Results of the analysed defect configurations indicate that the influence of gap defects is only relevant under small impact energy values. However, in the case of damage tolerance, the residual compressive strength after impact does not present significant differences to that of conventional straight fibre laminates. This indicates that the strength reduction is driven mainly by the damage caused by the impact event rather than by the influence of manufacturing-induced defects

Descripció de la tipologia d'usuaris derivats al servei de Teràpia Ocupacional Domiciliària a la comarca d'Osona: estudi descriptiu preliminar

Introducció Aquest treball, aborda l'atenció domiciliaria a les persones amb dependència des de la perspectiva de la teràpia ocupacional a la comarca d’Osona. Conèixer aquesta tipologia de persones i la seva problemàtica, ha de servir per adaptar les infraestructures d’aquests serveis a fi de donar millor resposta a les seves necessitats. Objectiu Descriure la tipologia d'usuaris que es deriven al servei de Teràpia Ocupacional Domiciliària a la comarca d'Osona Metodologia S'ha realitzat un estudi descriptiu preliminar d'una mostra (n=65) de usuaris de la base de dades del Banc D'ajudes Tècniques (BAT Osona) del Consell Comarcal d'Osona. En aquest estudi s'han analitzat les variables de sexe, edat, nivell funcional, diagnòstic, situació familiar, agents derivadors, motius de derivació i problemàtica principal detectada. Resultats S'indica un perfil femení de la mostra (72,09%), amb una mitjana d'edat de 74,41 anys. A nivell funcional, la mitjana de puntuació ha estat de 65 punts en l'Ìndex de Barthel, en persones amb patologia osteoarticular en el 18,60% dels casos. La situació familiar situa un perfil compartit de persones que viuen en família (41,86%) o soles (39,53%). En les derivacions al servei, el 58,13% dels casos es fa des dels Ajuntaments i per dificultats en el quarto de bany (46,51%). La problemàtica més detectada en aquests domicilis és la dificultat per l'accés a la banyera (67,40%). Conclusió Aquests resultats ens indiquen una clara tipologia de persones que s’han d’atendre i unes problemàtiques en la seva vivenda que provoquen serioses dificultats de desenvolupament funciona. Es precís, en futures investigacions acotar encara més aquets perfils i problemàtiques a fi de precisar les estratègies d’intervenció i optimitzar millor aquest tipus de recursos.