Search results for "NODAL"

A molecular dynamics study of large-scale reversible aggregation of anisotropic particles

1992

We report findings of 1000 ps molecular dynamics simulations of a bidimensional system of 4050 Lennard–Jones particles with electric dipoles, undergoing spinodal separation. This simple system is used to model the reversible aggregation of building blocks bearing specific and fixed adhesion sites at their surface. Aggregation regions so obtained resemble images of self-assembled biological structures. Statistical analyses of these regions evidence the interplay of thermodynamic instability and of interaction range between the attachment sites. They also illustrate some basic aspects of the morphogenesis of extended biomolecular/cellular structures, self-organized from initially homogeneous …

Spherically averaged versus angle-dependent interactions in quadrupolar fluids

2008

Employing simplified models in computer simulation is on the one hand often enforced by computer time limitations but on the other hand it offers insights into the molecular properties determining a given physical phenomenon. We employ this strategy to the determination of the phase behaviour of quadrupolar fluids, where we study the influence of omitting angular degrees of freedom of molecules via an effective spherically symmetric potential obtained from a perturbative expansion. Comparing the liquid-vapor coexistence curve, vapor pressure at coexistence, interfacial tension between the coexisting phases, etc., as obtained from both the models with the full quadrupolar interactions and th…

Morphometry and comparative histology of sinus and atrioventricular nodes in humans and pigs and their relevance in the prevention of nodal arrhythmi…

2019

The cardiac conduction system is a network structure that allows the initiation and fast propagation of electrical impulses that trigger the electrical depolarization of the myocardial tissue. The purpose of this work is to study the histological and morphometric characteristics of the different components of the sinus and atrioventricular nodes in humans and pigs and their relationship with supraventricular arrhythmias. In this study, we describe the morphometry of the sinus and atrioventricular nodes of 10 adult humans and 10 pig hearts. A computerized morphometric study has been carried out, where we determined the number of cells that compose the nodes as well as different parameters re…

A rare case report of variable degrees of atrioventricular block during atrioventricular nodal reentrant tachycardia

2020

Thermodynamics of pseudo-ternary systems as a tool to predict the morphologies of cellulose acetate/polystyrene blends cast from tetrahydrofuran solu…

2003

Abstract The demixing behavior of the ternary system THF/CA/PS (tetrahydrofuran/cellulose acetate/polystyrene) was investigated at 25 °C. Cloud point measurements show that the system exhibits a large miscibility gap caused by the incompatibility of CA and PS. Both ends of the experimentally determined tie lines are located inside the two-phase area of the phase diagram. By means of the measured critical composition of the ternary system and the Flory–Huggins interaction parameters published for two of the binary subsystems ( χ CA/THF =0.442 and χ PS/THF =0.475) the polymer/polymer interaction parameter was adjusted (directly minimizing the Gibbs energy) to χ CA/PS =0.057. These thermodynam…

Formation of metastable structures by phase separation triggered by initial composition gradients in thin films.

2012

Phase separation kinetics of a binary (A,B) mixture contained in a thin film of thickness D induced by a quench from the one-phase region into the miscibility gap is studied by simulations using a Cahn-Hilliard-Cook model. The initial randomly mixed state (50% A, 50% B) contains a concentration gradient perpendicular to the film, while the surfaces of the film are "neutral" (no preference for either A or B). In thermal equilibrium, a pattern of large A-rich and B-rich domains must result, separated by domain walls oriented perpendicularly to the external surfaces of the thin film. However, it is shown that for many choices of D and the strength of the initial gradient Ψ(g), instead a very l…

Microcanonical Determination of the Interface Tension of Flat and Curved Interfaces from Monte Carlo Simulations

2012

The investigation of phase coexistence in systems with multi-component order parameters in finite systems is discussed, and as a generic example, Monte Carlo simulations of the two-dimensional q-state Potts model (q=30) on LxL square lattices (40<=L<=100) are presented. It is shown that the microcanonical ensemble is well-suited both to find the precise location of the first order phase transition and to obtain an accurate estimate for the interfacial free energy between coexisting ordered and disordered phases. For this purpose, a microcanonical version of the heatbath algorithm is implemented. The finite size behaviour of the loop in the curve describing the inverse temperature vers…

Extranodal extension in N1-adenocarcinoma of the pancreas and papilla of Vater: A systematic review and meta-analysis of its prognostic significance

2016

The aim of the study was to investigate the prognostic role of extranodal extension (ENE) of lymph node metastasis in adenocarcinoma of the pancreas (PDAC) and papilla [cancer of the papilla of Vater (CPV)]. A PubMed and SCOPUS search from database inception until 5 January 2015 without language restrictions was conducted. Eligible were prospective studies reporting data on prognostic parameters in individuals with PDAC and/or CPV, comparing participants with the presence of ENE (ENE +) with those with intranodal extension (ENE). Data were summarized using risk ratios for number of deaths/recurrences and hazard ratios for time-dependent risk related to ENE+, adjusted for potential confounde…

Multiple solutions for (p,2)-equations at resonance

2019

We consider a nonlinear nonhomogeneous Dirichlet problem driven by the sum of a p-Laplacian and a Laplacian and a reaction term which is (p− 1)-linear near ±∞ and resonant with respect to any nonprincipal variational eigenvalue of (−∆p, W01,p(Ω)). Using variational tools together with truncation and comparison techniques and Morse Theory (critical groups), we establish the existence of six nontrivial smooth solutions. For five of them we provide sign information and order them.

Medikamentu administrēšana vispārējās aprūpes nodaļā

2021

Bakalaura darba tēma – „Medikamentu administrēšana vispārējās aprūpes nodaļā” aktualitāte pamatota ar to, ka mūsdienās arvien vairāk parādās kļūdas medikamentu administrēšanā. Bakalaura darba mērķis ir noskaidrot kāda ir medikamentu administrēšana vispārējas aprūpes nodaļās. Darbā ir izvēlēta kvantitatīvā pētniecības metode – anketa. Darba hipotēze ir apstiprinājusies daļēji, jo pastāv kļūdu iespēja pareizā medikamentu administrēšanā vispārējās aprūpes nodaļā, kas var ietekmēt pacientu atveseļošanos. Atslēgas vārdi: medikamenti, administrēšana, vispārējās aprūpes nodaļa.