Search results for "DICS"

Microfluidic Pumping by Micromolar Salt Concentrations

2017

An ion-exchange-resin-based microfluidic pump is introduced that utilizes trace amounts of ions to generate fluid flows. We show experimentally that our pump operates in almost deionized water for periods exceeding 24h and induces fluid flows of um/s over hundreds of um. This flow displays a far-field, power-law decay which is characteristic of two-dimensional (2D) flow when the system is strongly confined and of three-dimensional (3D) flow when it is not. Using theory and numerical calculations we demonstrate that our observations are consistent with electroosmotic pumping driven by umol/L ion concentrations in the sample cell that serve as 'fuel' to the pump. Our study thus reveals that t…

Preparation of actuating fibres of oriented main-chain liquid crystalline elastomers by a wetspinning process

2011

We present a versatile method to prepare oriented fibres with a defined thickness from main-chain liquid crystalline elastomers. A microfluidic setup is utilized to inject a solution of a photocrosslinkable smectic A main-chain polymer into a co-flowing stream of silicone oil. Diffusion of the solvent into the oil yields solid polymer filaments that are crosslinked in a continuous way by UV-irradiation. The obtained fibres are highly oriented and show a reversible and significant contraction during the liquid crystal's phase transition.

Microstructured Reactors for Polymer Synthesis: A Renaissance of Continuous Flow Processes for Tailor-Made Macromolecules?

2008

Organic synthesis in microfluidic devices has attracted increasing interest in recent years. However, little efforts had been undertaken to exploit this novel technology for polymer chemistry until several recent studies demonstrated the interesting potential of microreactors for the synthesis and modification of polymers. In fact, anionic polymerizations in continuous capillary flow-tube systems were established already in 1962 in pioneering work by Szwarc. Subsequent work focused on detailed kinetic analyses in such reactors. The present article explores different current strategies developed by several research groups to realize bulk and solution polymerizations using continuous flow mic…

Exercise as an antioxidant: it up-regulates important enzymes for cell adaptations to exercise

2006

Abstract Aims. – To assess the role of the reactive oxygen species (ROS) in cell signalling and in the regulation of gene expression. Methods. – Exercise causes oxidative stress only when exhaustive. Strenuous exercise causes oxidation of glutathione, release of cytosolic enzymes, and other signs of cell damage. We have tested this hypothesis by studying the effect of inhibition of ROS production by allopurinol (an inhibitor of xanthine oxidase, a free radical generating enzyme) on cell signalling pathways in marathon runners and in rats submitted to exhaustive exercise by running on a treadmill. Results. – Exercise caused an activation of NF-κB in lymphocytes from marathon runners which wa…

Cathepsin L in Normal and Pathological Bone Remodeling

2011

Abstract Cathepsin L is a ubiquitous lysosomal cysteine endopeptidase that is mainly involved in the metabolic turnover of intracellular proteins. However, it is now well established that this enzyme may also be implicated in the regulation of other important biological processes includ- ing bone resorption. Therefore, altered expression levels of Cathepsin L may result in disturbances of bone homeo- stasis and, eventually, in the onset of pathological condi- tions associated with altered bone turnover. These observations support the concept that Cathepsin L may be regarded as an additional target for the development of novel therapeutic options for the treatment of patients with bone disea…

Effects of strength and endurance training on antioxidant enzyme gene expression and activity in middle-aged men

2007

This study was aimed at investigating the effects of a 21-week period of progressive strength or endurance training on peripheral blood mononuclear cells (PBMC) antioxidant enzyme gene expression and activity in healthy middle-aged untrained men. Strength (n=11) and endurance (n=12) training were performed twice a week, including resistance exercises to activate all the main muscle groups or cycle-ergometer pedaling, respectively. mRNA levels of catalase, glutathione peroxidase (GPx), mitochondrial superoxide dismutase (MnSOD) and cytosolic superoxide dismutase (CuZnSOD) were increased after 21 weeks of strength training, while endurance training induced significant changes only in MnSOD an…

Effect of chondroitin sulphate and glucosamine in combination in an animal model of osteoarthritis and osteoporosis

2014

MCP-1 and rantes levels in the sinovium of osteoarthritic patients are reduced after treatement with chondroitin sulfate but not with paracetamol

2012

Klīnisko rezultātu novērtēšana pēc ceļa locītavu endoprotezēšanas

2016

Novecojušā sabiedrībā ar pieaugošo dzīves ilgumu, pieaug arī pieprasījums pēc pilnīgas ceļa locītavas aizvietošanas. Tajā pašā laikā cilvēki sešdesmit un septiņdesmit gadu vecumā ir daudz aktīvāki kā iepriekšējā paaudze un prasīgāki attiecībā uz mobilitāti. Klīniskais iznākums pilnīgai ceļa locītavas aizvietošanai ir mainīgs, jo viens no pieciem pacientiem nav apmierināts pēc operācijas. Ir vairāki gan ar pacientu saistīti, gan ar veselības aprūpi saistīti faktori, kas ietekmē pilnīgas ceļa locītavas aizvietošanas iznākumu. Mērķis ir apskatīt publicēto literatūru un parādīt gan ar pacientu, gan ar veselības aprūpi saistītos faktorus, kas ietekmē pilnīgas ceļa locītas aizvietošanas iznākumu.

Social integration in sports clubs: individual and organisational factors in a European context

2019

Sports clubs are often perceived as important mediums for social integration, but the empirical evidence to support this claim is limited. This article sets out to identify individual and organisational characteristics that are conducive to social integration of members and volunteers. Drawing on survey data from 13,000 members and volunteers in ten European countries, an exploratory factor analysis identified three dimensions of social integration. They match the overall conceptual distinction between socio-cultural and socio-affective integration and the sub-division of socio-affective integration into ‘interaction’ and ‘identification’. Multilevel regression analyses examined the relevan…