Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Synthesis of Metal-containing Polymers via Ring Opening Metathesis Polymerization (ROMP). Part II: Polymers Containing Transition Metals

Abstract: Following from Part I (this journal, 18(1), 2008), dedicated to main group metal containing polymers obtained by ROMP, the application of the same progressive concept to prepare polymers having this time transition metals in the side- or main-chain is here critically overviewed. These TMC polymers were produced through ROMP reactions promoted by Schrock’s Mo-carbene or the Grubbs’ Ru-carbene catalysts, the most recent and unique methodology for obtaining wished for structures. While discussing main aspects of these target-driven syntheses, as well as properties and applications of the neutral and cationic transition metal containing polymers, emphasis is laid upon organoiron macromolecules based on ferrocene scaffolds. Special attention is given to electrochemical behavior and thermal characteristics. Topics also cover polymers with other transition metals such as Co, Ni, Ru, Pd and Pt, which are important for generating zero valent metal nanoclusters in polymer films. Finally highlighted are some illustrative examples of metal-linked, metallodendrimers and hyperbranched, dendritic and star polymers.

Fixed domain approaches in shape optimization problems

Abstract: This work is a review of results in the approximation of optimal design problems, defined in variable/unknown domains, based on associated optimization problems defined in a fixed ?hold-all? domain, including the family of all admissible open sets. The literature in this respect is very rich and we concentrate on three main approaches: penalization?regularization, finite element discretization on a fixed grid, controllability and control properties of elliptic systems. Comparison with other fixed domain approaches or, in general, with other methods in shape optimization is performed as well and several numerical examples are included.

The cones of effective cycles on projective bundles over curves

Abstract: The study of the cones of curves or divisors on complete varieties is a classical subject in Algebraic Geometry (cf. [4,9,10]) and it still is an active research topic (cf. [1,11] or [2]). However, little is known if we pass to higher (co)dimension. In this paper we study this problem in the case of projective bundles over curves and describe the cones of effective cycles in terms of the numerical data appearing in a Harder–Narasimhan filtration. This generalizes to higher codimension results of Miyaoka and others ([3,15]) for the case of divisors. An application to projective bundles over a smooth base of arbitrary dimension is also given. Given a smooth complex projective variety X of dimension n, consider the vector spaces

Osteoblast ontogeny and implications for bone pathology: an overview

Abstract: Osteoblasts are specialized mesenchyme-derived cells accountable for bone synthesis, remodelling and healing. Differentiation of osteoblasts from mesenchymal stem cells (MSC) towards osteocytes is a multi-step process strictly controlled by various genes, transcription factors and signalling proteins. The aim of this review is to provide an update on the nature of bone-forming osteoblastic cells, highlighting recent data on MSC—osteoblast—osteocyte transformation from a molecular perspective and to discuss osteoblast malfunctions in various bone diseases. We present here the consecutive stages occurring in the differentiation of osteoblasts from MSC, the transcription factors involved and the role of miRNAs in the process. Recent data concerning the pathogenic mechanisms underlying the loss of bone mass and architecture caused by malfunctions in the synthetic activity and metabolism of osteoblasts in osteoporosis, osteogenesis imperfecta, osteoarthritis and rheumatoid arthritis are discussed. The newly acquired knowledge of the ontogeny of osteoblasts will assist in unravelling the abnormalities taking place during their differentiation and will facilitate the prevention and/or treatment of bone diseases by therapy directed against altered molecules and mechanisms.