First-Principles Study of Optical Absorption Energies, Ligand Field and Spin-Hamiltonian Parameters of Cr³⁺ Ions in Emeralds

Herein, we study the electronic structure, energies, and vibronic structure of optical d-d transitions of Cr3+ ions doped in beryl (Be3Si6Al2O18:Cr3+, emerald). A computational protocol is developed that combines periodic density functional theory (for modeling of the bulk crystalline lattice of emerald) and the multireference configuration interaction complete active space self-consistent field method supplemented with n-electron valence second-order perturbation theory (for the calculation of the energy levels, wave functions, and spin-Hamiltonian and ligand-field parameters of the trigonal Cr3+ centers in the [CrO6]9– clusters embedded in an extended point charge field). Ligand-field parameters were extracted from mapping the effective ligand-field Hamiltonian onto the full many-particle Hamiltonian from one side and from a direct fit to energies of computed d-d transitions on the other side. These have been analyzed using ab initio ligand-field theory. The quality of the theoretical predictions is critically assessed through a detailed comparison with the available experimental data

Non-local kinetic and macroscopic models for self-organised animal aggregations

The last two decades have seen a surge in kinetic and macroscopic models derived to investigate the multi-scale aspects of self-organised biological aggregations. Because the individual-level details incorporated into the kinetic models (e.g., individual speeds and turning rates) make them somewhat difficult to investigate, one is interested in transforming these models into simpler macroscopic models, by using various scaling techniques that are imposed by the biological assumptions of the models. However, not many studies investigate how the dynamics of the initial models are preserved via these scalings. Here, we consider two scaling approaches (parabolic and grazing collision limits) that can be used to reduce a class of non-local 1D and 2D models for biological aggregations to simpler models existent in the literature. Then, we investigate how some of the spatio-temporal patterns exhibited by the original kinetic models are preserved via these scalings. To this end, we focus on the parabolic scaling for non-local 1D models and apply asymptotic preserving numerical methods, which allow us to analyse changes in the patterns as the scaling coefficient ϵ is varied from ϵ=1 (for 1D transport models) to ϵ=0 (for 1D parabolic models). We show that some patterns (describing stationary aggregations) are preserved in the limit ϵ→0, while other patterns (describing moving aggregations) are lost. To understand the loss of these patterns, we construct bifurcation diagrams

Esophageal resection- experience in center of general surgery and liver transplantation “Dan Setlacec” 2001-2011

Institultul Clinic Fundeni, Clinica Chirurgie Generală şi Transplant Hepatic “Dan Setlacec”, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Chirurgia rezecţională esofagiană este complexă prin varietatea substratului lezional, multitudinea căilor de abord precum şi terenul biologic frecvent alterat al pacienţilor. Scopul acestei lucrări este analiza rezultatelor postoperatorii imediate şi tardive în rândul pacienţilor supuşi rezecţiei esofagiene în Centrul de Chirurgie Generală şi Transplant Hepatic ”Dan Setlacec” în perioada 2001-2011.Esophageal resection is a demanding surgical task due to various lesional substrat and type of surgical approach and, often, .alterated biological field of patients.The aim of this study is to analyze immediate and late outcome of patients reffered for esophageal resection in Center for General Surgery and Liver Transplantation “Dan Setlacec” from Fundeni Clinical Institute along a decade (2001-2011)

Preface. Bifurcations and Pattern Formation in Biological Applications

In the preface we present a short overview of articles included in the issue "Bifurcations and pattern formation in biological applications" of the journal Mathematical Modelling of Natural Phenomena

Miniinvasive approach in esophageal tumoral pathology

Institultul Clinic Fundeni - Clinica Chirurgie Generală şi Transplant Hepatic “Dan Setlacec”, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Chirurgia esofagiană este grevată de morbiditate şi mortalitate crescute legate în special de trauma chirurgicală. Abordul miniinvaziv are ca scop optimizarea acestor parametrii prin diminuarea traumei chirurgicale. Este prezentată experienţa Centrului de Chirurgie Generală şi Transplant Hepatic “Dan Setlacec” din Institutul Clinic Fundeni în abordul miniinvaziv în patologia tumorală esofagiană.Morbidity and mortality in esophageal resection remain high, due especially to surgical injury. Miniinvasive surgical approach is used in order to decrease both parameters, by lowering surgical associated trauma.The aim of this study is to analyze the outcome of patients reffered for miniinvasive esophageal resection in Center for General Surgery and Liver Transplantation “Dan Setlacec” from Fundeni Clinical Institute

Modelling Stochastic and Deterministic Behaviours in Virus Infection Dynamics

Many human infections with viruses such as human immunodeficiency virus type 1 (HIV--1) are characterized by low numbers of founder viruses for which the random effects and discrete nature of populations have a strong effect on the dynamics, e.g., extinction versus spread. It remains to be established whether HIV transmission is a stochastic process on the whole. In this study, we consider the simplest (so-called, 'consensus') virus dynamics model and develop a computational methodology for building an equivalent stochastic model based on Markov Chain accounting for random interactions between the components. The model is used to study the evolution of the probability densities for the virus and target cell populations. It predicts the probability of infection spread as a function of the number of the transmitted viruses. A hybrid algorithm is suggested to compute efficiently the dynamics in state space domain characterized by a mix of small and large species densities