Influence of perineural invasion in predicting overall survival and disease-free survival in patients With locally advanced gastric cancer

Background The aim of the present study was to evaluate the prognostic significance of perineural invasion (PNI) in locally advanced gastric cancer patients who underwent D2 gastrectomy and adjuvant chemotherapy. Methods The records of a series of 103 patients undergoing D2 gastrectomy with curative intent combined with adjuvant chemotherapy from January 2004 to December 2014 were retrospectively reviewed. Results PNI was positive in 47 (45.6%) specimens. The 1-, 3-, and 5-year overall survival rates were 81%, 55%, and 42%, respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 76%, 57%, and 49%, respectively. A multivariate analysis showed that age number of positive lymph nodes, T stage, and PNI were independently associated with overall survival. Regarding DFS, the multivariate analysis showed that only PNI was independently associated with DFS. Conclusions PNI and T stage and positive lymph nodes are independent markers of poor prognosis in patients with gastric cancer. PNI should be incorporated in the postoperative staging system for planning follow-up after surgery and in our opinion to propose more aggressive postoperative therapies in PNI-positive patients

Dynamics of a deformable self-propelled particle under external forcing

We investigate dynamics of a self-propelled deformable particle under external field in two dimensions based on the model equations for the center of mass and a tensor variable characterizing deformations. We consider two kinds of external force. One is a gravitational-like force which enters additively in the time-evolution equation for the center of mass. The other is an electric-like force supposing that a dipole moment is induced in the particle. This force is added to the equation for the deformation tensor. It is shown that a rich variety of dynamics appears by changing the strength of the forces and the migration velocity of self-propelled particle

Topology by Design in Magnetic nano-Materials: Artificial Spin Ice

Artificial Spin Ices are two dimensional arrays of magnetic, interacting nano-structures whose geometry can be chosen at will, and whose elementary degrees of freedom can be characterized directly. They were introduced at first to study frustration in a controllable setting, to mimic the behavior of spin ice rare earth pyrochlores, but at more useful temperature and field ranges and with direct characterization, and to provide practical implementation to celebrated, exactly solvable models of statistical mechanics previously devised to gain an understanding of degenerate ensembles with residual entropy. With the evolution of nano--fabrication and of experimental protocols it is now possible to characterize the material in real-time, real-space, and to realize virtually any geometry, for direct control over the collective dynamics. This has recently opened a path toward the deliberate design of novel, exotic states, not found in natural materials, and often characterized by topological properties. Without any pretense of exhaustiveness, we will provide an introduction to the material, the early works, and then, by reporting on more recent results, we will proceed to describe the new direction, which includes the design of desired topological states and their implications to kinetics.Comment: 29 pages, 13 figures, 116 references, Book Chapte

Are pre-service Primary School teachers prepared to teach science by inquiry?

[EN] Inquiry-based science education (IBSE) focuses on the development of science process skills. This teaching methodology has been shown to be especially effective during Primary School as it allows children to explore and confront their own ideas about Nature. Also, a methodology based on process skills is coherent with the main purpose of this educational stage where children need to learn to do things. In order to implement a methodology based on science process skills Primary teachers need to know to use science process skills, and how to teach them. In this paper we address if Spanish pre-service teachers are able to implement IBSE. We focus on pre-service Primary School teachers and compare our results with in-service teachers and a random sample of non-teachers. We explore their level of knowledge about science process skills and if pre-service teachers know how to develop an inquiry-based learning sequence. An overview of the situation of science education and teaching of scientific skills among the degrees on Primary Education in Spain is also presented. Our results show that pre-service teachers have a lack of knowledge on science process skills and fail when they attempting to build a learning sequence based on inquiry.Montero-Pau, J.; Tierno, SP.; Tuzon, P. (2017). Are pre-service Primary School teachers prepared to teach science by inquiry?. En Proceedings of the 3rd International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 1294-1301. https://doi.org/10.4995/HEAD17.2017.55861294130

Active Brownian Particles. From Individual to Collective Stochastic Dynamics

We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

Engineering tunable fractional Shapiro steps in colloidal transport

Shapiro steps are quantized plateaus in the velocity-force or velocity-torque curve of a driven system, when its speed remains constant despite an increase in the driving force. For microscopic particles driven across a sinusoidal potential, integer Shapiro steps have been observed. By driving a single colloidal particle across a time-modulated, non-sinusoidal periodic optical landscape, we here demonstrate that fractional Shapiro steps emerge in addition to integer ones. Measuring the particle position via individual particle tracking, we reveal the underlying microscopic mechanisms that produce integer and fractional steps and demonstrate how these steps can be controlled by tuning the shape and driving protocol of the optical potential. The flexibility offered by optical engineering allows us to generate a wide range of potential shapes and to study, at the single-particle level, synchronization behavior in driven soft condensed matter systems