Recent developments in the ring-opening polymerization of epsilon-caprolactone and derivatives initiated by tin(IV) alkoxides

in Macromolecular Symposia (2004), 215

The macromolecular engineering of aliphatic polyesters by Ring-Opening Polymerization (ROP) initiated by aluminum alkoxides is now well established. Tin (IV) alkoxides are less popular, mainly because of ... [more ▼]

The macromolecular engineering of aliphatic polyesters by Ring-Opening Polymerization (ROP) initiated by aluminum alkoxides is now well established. Tin (IV) alkoxides are less popular, mainly because of a poorer control of the chain growth. This paper discusses some recent examples from CERM, showing that tin (IV) alkoxides can advantageously replace the aluminum counterparts as ROP initiators. For instance, they can initiate successfully the Ring-Opening Polymerization of α-chloro-ε-caprolactone and dioxepane-2-one. They are also very promising initiators for ROP in supercritical CO2 and for the synthesis of clay/aliphatic polyester nanocomposites. [less ▲]

Recent developments on composite connections: behaviour of joints subjected to sagging bending moments and presentation of a free design dedicated software

in EUROSTEEL 2008, 5th European Conference on Steel and Composite Structures (2008, September)

In Eurocode 4, design rules are suggested for the evaluation of the mechanical properties of structural steel-concrete composite joints (rotational stiffness, resistance and ductility). These rules cover ... [more ▼]

In Eurocode 4, design rules are suggested for the evaluation of the mechanical properties of structural steel-concrete composite joints (rotational stiffness, resistance and ductility). These rules cover situations where the joints are subjected to moments and shear forces, but in hogging regions only. Recently, researches have been conducted on the behaviour of composite joints subjected to sagging bending moments and to combined bending moments and axial loads, types of loadings which appear in composite frame further to a column loss. In the present paper, recent developments allowing to extend the EC4 design rules to joints in sagging regions (loading which can occur, for instance, in sway composite frames) are presented and the proposed method is validated through comparisons with experimental test results. Also, an easy-to-apply design software (which will be freely available), applying the rules recommended in Eurocode 4 in a safe and easy way, is described. [less ▲]

Recent discoveries of new hantaviruses widen their range and question their origins.

in Annals of the New York Academy of Sciences (2008), 1149

Hantaviruses belong to the Bunyaviridae family. While usually hosted by wild mammals, they are potentially pathogenic for humans, and several serologically distinct groups associated with different ... [more ▼]

Hantaviruses belong to the Bunyaviridae family. While usually hosted by wild mammals, they are potentially pathogenic for humans, and several serologically distinct groups associated with different syndromes have been identified. Yet, investigations have mostly been conducted where human infections by hantaviruses constitute a real and well-identified public health problem, i.e., the holarctic and neotropical areas. Some hantaviruses have also been described from a Suncus murinus in India and a Bandicota indica in Thailand. In addition, recent investigations in Cambodia revealed new Hantavirus types. More recently, two new Hantavirus species were described: Sangassou from a Hylomyscus simus, and Tanganya from a Crocidura theresae, both from Africa (Guinea), thus strongly questioning the current views about geographic range, evolution, and epidemiology of hantaviruses. In such a framework, we have conducted a survey of Hantavirus diversity in Southeast Asia which allows us to isolate the Thailand virus and address questions about the taxonomy of their rodent hosts. Here we present a molecular analysis of representatives of all currently known Hantavirus species, thus allowing the comparison between the newly described ones with a large range sample of rodent hantaviruses. Our results clearly point to the presence of a particular lineage of hantaviruses in Southeast Asia. It also strongly suggests that new viruses, additional mammalian hosts and different related syndromes in humans are likely to be discovered in the near future, particularly in Southeast Asia and in Africa, where Muridae rodents are highly diversified. Furthermore, additional work is also urgently needed to investigate the hantaviruses associated with Crociduridae and Soricidae. [less ▲]

Recent Evolution of atmospheric OCS above the Jungfraujoch station : implications for the stratospheric aerosol layer.

in Proceedings of the Atmospheric Spectroscopy Applications. (2005)

Recent evolution of the status of the European mink (Mustela lutreola) and of the otter (Lutra lutra) in France.

in III International Symposium "Semiaquatische Säugetiere und ihre Lebenräume (1999, May)

Recent experience with a respiratory monitoring system in intensive care

in Acta Anaesthesiologica Belgica (1975), 26

Recent insights into Protein Phosphatase 2A structure and regulation : The reason why PP2A is no longer considered as a lazy passive housekeeping enzyme

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(1), 243-252

Reversible protein phosphorylation is a major intracellular mechanism for controlling many important physiological activities. In the past, most of the attention was focused primarily on protein kinases ... [more ▼]

Reversible protein phosphorylation is a major intracellular mechanism for controlling many important physiological activities. In the past, most of the attention was focused primarily on protein kinases and on their regulation, mainly because phosphatases were then viewed as simple housekeeping enzymes. But advances in the understanding of phosphatases make now clear that protein phosphatases are dynamic and highly regulated enzymes and are as important as kinases in the regulation of cellular processes involving protein phosphorylation. Protein phosphatase 2A (PP2A) is a very abundant -it accounts for as much as 1% of total cellular protein-, ubiquitous and remarkably conserved enzyme. By dephosphorylating a plethora of cellular proteins, it is involved in the regulation of nearly all cellular activities. [less ▲]

Recent investigations on composite sway frames

in Journal of Civil Engineering & Management (2004), X(1), 15-23

A modern design code for composite construction such as Eurocode 4 limits its scope to “non-sway buildings” with efficient bracing systems. Therefore, it gives mainly rules to analyse and to check ... [more ▼]

A modern design code for composite construction such as Eurocode 4 limits its scope to “non-sway buildings” with efficient bracing systems. Therefore, it gives mainly rules to analyse and to check structural elements like beams, columns, slabs and joints. However, in the last years, the construction of taller buildings and larger industrial halls without wind bracing systems is susceptible to make global instability a relevant failure mode, what is not yet covered by Eurocode 4. For three years, in the framework of a European research project funded by the European Community for Steel and Coal (ECSC), in which Liège University was deeply involved, intensive experimental, numerical and theoretical investigations have been carried out. The latter aimed at improving the knowledge in the field of sway composite frames and at developing appropriate design rules. The rotational behaviour of the beam-to-column composite joints is one of the key aspects of the problem to which a special attention has been paid. This paper presents numerical and analytical studies carried out at Liège University, as part of the above European project, with the objective to investigate the behaviour of 2D composite sway frames under static loading. Particular phenomena put into sight through different analyses are illustrated herein. [less ▲]

The recent labour unrest in China and the politics of handling collective mobilization by the Party-state

Report (2011)

Recent landslide activity in Manaihan, E Belgium

in Landslides (2004), 1

Past landslides have been recognized in the Battice area in E-Belgium. In contrast to the other inactive landslides, the Manaihan landslide responded immediately to heavy rainfall events in the last two ... [more ▼]

Past landslides have been recognized in the Battice area in E-Belgium. In contrast to the other inactive landslides, the Manaihan landslide responded immediately to heavy rainfall events in the last two decades. This study aims to map its spatial extent and the dominant surface features; to measure surface displacement using GPS; to investigate subsurface structure with Cone penetration test (CPT) and corings; and to determine the depth of the shear surface by inclinometers. Results show a partial landslide reactivation. Surface velocities range between 20 and 40 cm/year and are strongly dependent on winter rainfall. CPT results give clear boundaries between the landslide mass and the undisturbed bedrock in the head scarp. Distinct shear surfaces have been determined with displacement rates up to 15.8 mm in 21 days. Further research should apply geophysical methods for two-dimensional information on the ground, investigate geotechnical properties of the landslide mass, model slope instability, and determine the influence of a sewage pipe crossing the central landslide mass as a potential cause for landslide activity. [less ▲]