National Scientific and Technical Research Council

About: National Scientific and Technical Research Council is a government organization based out in Buenos Aires, Argentina. It is known for research contribution in the topics: Population & Catalysis. The organization has 36143 authors who have published 62683 publications receiving 1013255 citations. The organization is also known as: CONICET.

Reaction-induced phase separation in modified thermosetting polymers

Abstract: Thermosetting polymers are frequently used in formulations, including rubbers, thermoplastic polymers or oils, etc, in an amount of the order of 2–50 wt% with respect to the thermoset. This extra component, called the modifier, may initially be immiscible or may phase-separate during cure. This last process, i.e the reaction-induced phase separation, is the subject of this review. A thermodynamic description of the process is made, using the Flory-Huggins equation at two approximation levels, i.e. a quasi-binary approach and a multicomponent treatment taking polydispersity of constituents into account. Thermodynamic factors affecting the phase separation process are thus established. Nucleation and growth (NG) and spinodal demixing (SD) are considered as possible phase separation mechanisms. Factors promoting one or the other process are discussed. The control of morphologies generated is analyzed on the basis of thermodynamic and kinetic arguments. Ideas for obtaining particular morphologies enhancing particular properties are put forward.

The Neuquén Basin: an overview

Abstract: The Neuquen Basin of Argentina and central Chile contains a near-continuous Late Triassic–Early Cenozoic succession deposited on the eastern side of the evolving Andean mountain chain. It is a polyphase basin characterized by three main stages of evolution: initial rift stage; subduction-related thermal sag; and foreland stage. The fill of the basin records the tectonic evolution of the central Andes with dramatic evidence for baselevel changes that occurred both within the basin and along its margins. The record of these changes within the mixed siliclastic–carbonate succession makes the basin an excellent field laboratory for sequence stratigraphy and basin evolution. The 4000 m-thick fill of the basin also contains one of the most complete Jurassic–Early Cretaceous marine fossil records, with spectacular finds of both marine and continental vertebrates. The basin is also the most important hydrocarbon-producing province in southern South America, with 280.4 10 m of oil produced and an estimated 161.9 10 m remaining. The principal components of the hydrocarbon system (source and reservoir) crop out at the surface close to the fields. The deposits of the basin also serve as excellent analogues to reservoir intervals worldwide. This paper aims to provide a brief introduction to the Neuquen Basin. It should provide a stepping stone for further reading and also for further studies. This paper also serves as an introduction to this Special Publication, which details the most recent work within the basin. The proposed goals of the Special Publication are as follows. . To present the Neuquen Basin as an integrated case study in sequence stratigraphy and basin analysis. . To document the latest developments in vertebrate and invertebrate palaeontology. . To consider the basin in the context of the structural evolution of the central Andes. . To document the latest studies on specific stratigraphic intervals in a way that allows the reader to build up a complete picture of the basin fill and the way in which the various depositional systems have evolved through time. . To present specific studies from the basin that highlights concepts and models in sequence stratigraphy that are exportable to other systems. Introduction to the Neuquen Basin The Neuquen Basin is located on the eastern side of the Andes in Argentina and central Chile, between 328 and 408S latitude (Figs 1 & 2). It covers an area of over 120 000 km (Yrigoyen 1991) and comprises a continuous record of up to 4000 m of stratigraphy. This Late Triassic– Early Cenozoic succession includes continental and marine siliciclastics, carbonates and evaporites that accumulated under a variety of basin styles (Fig. 3). The basin has a broadly triangular shape (Fig. 1) and two main regions are commonly recognized: the Neuquen Andes to the west, From: VEIGA, G. D., SPALLETTI, L. A., HOWELL, J. A. & SCHWARZ, E. (eds) 2005. The Neuquen Basin, Argentina: A Case Study in Sequence Stratigraphy and Basin Dynamics. Geological Society, London, Special Publications, 252, 1–14. 0305-8719/05/$15.00 # The Geological Society of London 2005. and the Neuquen Embayment to the east and SE. The majority of the Basin’s hydrocarbon fields are located in the Neuquen Embayment where most of the Mesozoic sedimentary record is in the subsurface and the strata are relatively undeformed. This is in contrast to the Andean region where Late Cretaceous–Cenozoic deformation has resulted in the development of a series of N–S-oriented fold and thrust belts (Aconcagua, Marlargue and Agrio fold and thrust belts, Fig. 2) that provide excellent outcrops of the Mesozoic successions. During present times and throughout much of its history the triangular Neuquen Basin has been limited on its NE and southern margins by wide cratonic areas of the Sierra Pintada Massif and the North Patagonian Massif, respectively (Fig. 1). The western margin of the basin is the Andean magmatic arc on the active western margin of the Gondwanan–South American Plate. This geotectonic framework and the highly complex history of the basin are largely controlled by changes in the tectonics on the western margin of Gondwana. The evolution and development of the basin can be considered in three stages (Fig. 3). 1. Late Triassic–Early Jurassic: prior to the onset of subduction on its western margin, Fig. 1. Sketch map of the Neuquen Basin showing the approximate location (boxes and stars) of the contributions included in this publication. 1, Ramos & Folguera; 2, Zapata & Folguera; 3, Aguirre-Urreta et al.; 4, McIlroy et al.; 5, Schwarz & Howell; 6, Veiga et al.; 7, Stromback et al.; 8, Doyle et al.; 9, Scasso et al.; 10, Sagasti; 11, Tyson et al.; 12, Morgans-Bells & McIlroy; 13, Gasparini & Fernandez; 14, Lazo et al.; 15, Coria & Salgado. J. A. HOWELL ET AL. 2

Galectins: matricellular glycan-binding proteins linking cell adhesion, migration, and survival.

Abstract: Galectins are a taxonomically widespread family of glycan-binding proteins, defined by at least one conserved carbohydrate-recognition domain with a canonical amino acid sequence and affinity for beta-galactosides Because of their anti-adhesive as well as pro-adhesive extracellular functions, galectins appear to be a novel class of adhesion-modulating proteins collectively known as matricellular proteins (which include thrombospondin, SPARC, tenascin, hevin, and disintegrins) Accordingly, galectins can display de-adhesive effects when presented as soluble proteins to cells in a strong adhesive state In this context, the de-adhesive properties of galectins should be considered as physiologically relevant as the proadhesive effects of these glycan-binding proteins This article focuses on the roles of mammalian galectins in cell adhesion, spreading, and migration, and the crossregulation of these functions Although careful attention should be paid when examining individual galectin functions due to overlapping distributions, these intriguing glycan-binding proteins offer promising possibilities for the treatment and intervention of a wide variety of pathological processes, including cancer, inflammation, and autoimmunity