An institutional study: Does Body Mass Index influence surgical approach, surgical morbidities, and outcomes in endometrial cancer patients?

Background: Endometrial Cancer (EC), the most common genital tract malignancy in women, is recognised to be associated with a high Body Mass Index (BMI). Objective: The aim of the study was to evaluate the impact of obesity on intra and post-operative morbidity for patients treated for EC. Materials and Methods: This was a retrospective observational study including patients with EC that were surgically treated at Hospital de la Santa Creu i Sant Pau during nine consecutive years. The patients were divided in groups according to BMI: <30 Kg/m2, ≥30-<40 Kg/m2 and ≥40 Kg/m2. Demographic and pathological characteristics, surgical outcomes, perioperative complications and long-term outcomes were recorded. Results: The study included 290 patients; 164 patients with BMI <30 Kg/m2(56.5%), 107 patients with ≥30-<40 Kg/m2 36.9%) and 19 patients with ≥40 Kg/m2(6.65%). Patients with BMI ≥40Kg/m2 were younger, presented a higher percentage of endometrioid histology (84.2%, p<0.01), well-differentiated tumours (73.7%, p<0.01) and were more frequently in the initial stages at diagnosis (94.7%) compared to the other groups. A significant percentage of the patients were operated on laparoscopically (88.7%, 88.8%, 94.7% respectively). No significant differences were found in the evaluation of the surgical outcomes. The results relative to complications showed an overall tendency toward increase in the ≥40 Kg/m2 BMI group but no statistical differences were identified among the groups in terms of complications or long-term outcomes. Conclusions: There was a rising trend towards increased complications with increasing BMI in the study population, however, this was found not to be statistically significant. Therefore, the optimisation of co-morbidities and the adaptation of surgical treatment is important for the management of obese patients with endometrial cancer. What is new?: The study allows the comparison between groups with different BMI in patients with endometrial cancer. Different surgical outcomes, intra operative, early, and late complications are clearly identified, and survival outcomes are also investigated in our study.

Statistical mechanics of Hamiltonian adaptive resolution simulations.

The Adaptive Resolution Scheme (AdResS) is a hybrid scheme that allows to treat a molecular system with different levels of resolution depending on the location of the molecules. The construction of a Hamiltonian based on the this idea (H-AdResS) allows one to formulate the usual tools of ensembles and statistical mechanics. We present a number of exact and approximate results that provide a statistical mechanics foundation for this simulation method. We also present simulation results that illustrate the theory.

Mechanisms for dynamic crack branching in brittle elastic solids: strain field kinematics and reflected surface waves.

We report on a numerical simulation study of dynamic fracture in strip-shaped plates in which we implement a fracture criterion that fully respects mode-I symmetry. The crack dynamics is studied as a function of the length of the initial notch. The cracks show accelerated straight motion until branching appears. We show that branching can be triggered by two different mechanisms: namely, the kinematics of the strain field and back-reflected surface waves traveling on the crack lip. We also propose a qualitative explanation for the kinematic branching mechanism in terms of the effects of the lattice discretization on Yoffe's stress field. The kinematic branching mechanism is understood by analyzing the disconnection times of the nodes ahead and aside of the crack tip.

Thermodynamically consistent mesoscopic fluid particle model.

We present a finite volume Lagrangian discretization of the continuum equations of hydrodynamics through the Voronoi tessellation. We then show that a slight modification of these discrete equations satisfies the first and second laws of thermodynamics. This is done by casting the model into the GENERIC structure. The GENERIC structure ensures thermodynamic consistency and allows for the introduction of correct thermal fluctuations in simple terms. In this way, we obtain a consistent discrete model for Lagrangian fluctuating hydrodynamics. Simulation results are presented that show the validity of the model for simulating hydrodynamic problems at mesoscopic scales.

Dynamic fracture in a discrete model of a brittle elastic solid

Dynamic fracture of brittle materials is studied by means of a molecular dynamics simulation of a two-dimensional (2D) lattice of point particles. By a particular discretization of the continuum equations of elasticity, we derive the Born model in such a way that the model parameters are related to the material properties. Numerical simulations are performed, which show a branching instability, under Mode I loading, occurring at a critical crack tip speed. The analysis of the dynamical stress tensor field near the tip shows a qualitative similarity to Yoffe's stress field.

Dynamical regimes in the dissipative particle dynamics model.

We discuss theoretically the behavior of the velocity autocorrelation function in the dissipative particle dynamics (DPD) model. Two dynamical regimes are identified depending on the dimensionless model parameters. For low values of the dimensional friction, a mean field behavior is observed in which the kinetic theory for the DPD model provides good predictions. For high values of the friction, collective hydrodynamic effects are dominant. We have performed numerical simulations that validate the theory presented.