Search results for "rigid"
showing 10 items of 188 documents
Topology-Sensitive Microfluidic Filter for Polymers of Varying Stiffness
2017
The separation of polymers based on their size, rigidity, and topology is an essential but also highly challenging task for nanoscience and engineering. Using hybrid molecular dynamics simulations that correctly take into account hydrodynamics, we have designed microfluidic channels for separating linear from ring polymers in dilute solutions. We establish that the transport velocity of the polymers is independent of their topology and rigidity when the channel walls are smooth and repulsive. However, when the walls are decorated with attractive spots arranged on lines parallel to the flow, ring polymers exhibit an order of magnitude higher transport velocity compared to linear chains. The …
Elastic properties of polymer interfaces: Aggregation of pure diblock, mixed diblock, and triblock copolymers
2002
Block copolymers adsorbing to an interface between two immiscible homopolymers modify the elastic constants of this interface. Within self-consistent field calculations for Gaussian chains, we determine how the bending constants vary in dependence on the block copolymer concentration and architecture. Four phenomena are discussed. (i) When a tricritical or isotropic Lifshitz critical point is approached in a ternary mixture by varying the concentration of diblock copolymers or changing temperature, the elastic constants vanish. We determine the corresponding power laws, and show that the de Gennes--Taupin criterium for the stability of lamellar phases against undulations and the Ginzburg-La…
Comb-Branched Polymers: Monte Carlo Simulation and Scaling
1996
The Monte Carlo simulation technique (the bond fluctuation model) has been used for the study of the equilibrium conformations of comb-branched polymers consisting of a long flexible main chain and side chains grafted at a regular separation onto the main chain. The solvent has been supposed to be good (athermal) for the main and side chains. The global conformation and the gyration radius of the polymer, as well as the local conformational structure of the comb, have been analyzed as functions of the length of the side chains and spacers. The effect of induced rigidity of the comb due to the interaction between side chains has been observed. We have found the results of the simulation to b…
Monotonicity Formulas for Harmonic Functions in RCD(0,N) Spaces
2023
We generalize to the RCD(0,N) setting a family of monotonicity formulas by Colding and Minicozzi for positive harmonic functions in Riemannian manifolds with nonnegative Ricci curvature. Rigidity and almost rigidity statements are also proven, the second appearing to be new even in the smooth setting. Motivated by the recent work in Agostiniani et al. (Invent. Math. 222(3):1033–1101, 2020), we also introduce the notion of electrostatic potential in RCD spaces, which also satisfies our monotonicity formulas. Our arguments are mainly based on new estimates for harmonic functions in RCD(K,N) spaces and on a new functional version of the ‘(almost) outer volume cone implies (almost) outer metric…
La dirigenza pubblica: criteri di identificazione e specialità della disciplina.
Nel tentativo di far luce sui maggiori coni d’ombra che emergono dalla relativa disciplina speciale del rapporto di lavoro, la tesi riflette l’esigenza di un ripensamento sistematico della figura del dirigente pubblico, nell’ottica di prospettare de iure condendo possibili correttivi. A tal fine, sono analizzate le peculiarità ed attribuzioni della dirigenza pubblica, in chiave storico-evolutiva, alla luce dei principi costituzionali e del processo riformatore che ha contrassegnato la magmatica materia, a tutt’oggi in atto. E’, altresì, rivolto uno sguardo comparativistico alla disciplina del personal directivo español, rivelandosi la stessa, speculare a quella del dirigente italiano quanto…
Parámetros ecocardiográficos de rigidez aórtica y su asociación con isquemia miocárdica silente en diabéticos tipo 2
2017
La rigidez aórtica (RAo) se ha relacionado con el aumento de la carga de trabajo cardíaco, afectación de la perfusión coronaria y desarrollo de disfunción diastólica (DD) del ventrículo izquierdo. Esta alteración es frecuente en los pacientes con diabetes mellitus (DM) en los que, por otra parte, la prevalencia de isquemia miocárdica silente (IMS), puede llegar a ser elevada. La RAo aumentada precede a las manifestaciones clínicas, incluyendo aquellas relacionadas con la afectación de las arterias coronarias, por lo que puede ser un vínculo entre la IMS y la DM. Diferentes métodos ecocardiográficos han estudiado la rigidez arterial. Con el modo M y el doppler tisular (DTI) se obtiene inform…
Behavioral and psychological flexibility in eating regulation among overweight adults
2016
Weight-loss programs are often based on self-control techniques and they commonly fail in long-term weight management. Identifying psychological processes that explain eating behaviors can help to develop more effective interventions for long-term weight management. This research examined how behavioral and psychological flexibility are related to eating regulation and weight management in overweight adults. The first goal was to study the effects of flexible vs. rigid restraint of eating on weight-loss maintenance and well-being. The second goal was to examine whether psychological flexibility and mindfulness, independently and together, explain intuitive eating regulation. The third goal …
El rol de las emociones del usuario en la evaluación de centros deportivos con actividades dirigidas
2017
Las emociones en la actividad física y su relación con otras variables como la satisfacción, la calidad del servicio, la intención futura y el valor percibido del usuario en centros deportivos cada día cobra mayor protagonismo dentro del área de gestión deportiva (Biscaia, Correira, Rosado, Maroco y Ross, 2012; Martín, O’Neill Hubbard y Palmer, 2008 Pedragosa, Biscaia y Correia, 2015). La mayoría de disciplinas estudian las emociones desde las áreas de la psicología y la neurofisiología-biología, cuyos campos de estudio relacionan los procesos mentales psicológicos y las respuestas motoras fisiológicas con las emociones que se generan en el ser humano (Andreu, 2003; Belmonte, 2007; Chóliz, …
A Practical Perspective : The Effect of Ligand Conformers on the Negative Image-Based Screening
2019
Negative image-based (NIB) screening is a rigid molecular docking methodology that can also be employed in docking rescoring. During the NIB screening, a negative image is generated based on the target protein’s ligand-binding cavity by inverting its shape and electrostatics. The resulting NIB model is a drug-like entity or pseudo-ligand that is compared directly against ligand 3D conformers, as is done with a template compound in the ligand-based screening. This cavity-based rigid docking has been demonstrated to work with genuine drug targets in both benchmark testing and drug candidate/lead discovery. Firstly, the study explores in-depth the applicability of different ligand 3D conformer…
Nueva era en el combate contra el cáncer: Evolución y cáncer: progreso y tratamiento de tumores
2013
L’oncohematologia ha assistit en les últimes dècades a importants avenços en el tractament i supervivència. La toxicitat derivada de la quimioteràpia clàssica i la necessitat de millorar l’eficàcia i tolerància als tractaments han fet que es desencadene un allau d’activitat investigadora que constantment proporciona fruits. Gran part d’aquest esforç s’ha enfocat al desenvolupament de «teràpies diana» dirigides contra determinades alteracions funcionals, clau per a la supervivència de la cèl·lula tumoral. Així es pretén aconseguir major eficàcia en el tractament i que el pacient pague un menor cost en toxicitat. Avenços en altres disciplines de l’oncologia com l’epidemiologia, la cirurgia i …