9,618 research outputs found
Prognostic factors and underlying mechanisms in chronic low back pain
Nonspecific chronic low back pain (CLBP) is generally approached from a biopsychosocial perspective. A variety of multidisciplinary treatments has been developed aimed at improving activity and participation of subjects with CLBP, but effectiveness is limited. One of the explanations could be the heterogeneity of the CLBP population, which makes it unlikely that all patients will benefit from the same generic treatment. As such, more insight is needed in the role of underlying biopsychosocial mechanisms in subjects with CLBP. Knowledge of these aspects is expected to provide a better match of treatment to the patientâs characteristics and improve the effectiveness of multidisciplinary treatments. The main aim of this thesis is to gain insight in these mechanisms, both in relation to treatment outcome, as in differences with respect to asymptomatic controls
Influence of spinal cord stimulation on evoked potentials by cutaneous electrical stimulation
In the past, limited research has been done to investigate the influence of spinal cord stimulation (SCS) for treatment of chronic pain on evoked potentials (EP). Further insight into the mechanism of SCS may provide explanations for unsatisfactory results with this therapy in certain subpopulations. It also might predict effectiveness of SCS. In previous research MEG responses were measured on median and tibial nerve stimulations in chronic pain patients with and without SCS (1). However, this stimulation method preferentially activates large myelinated proprioceptive fibres, leaving painrelated small fibres unrelated. We expect that the observation of pain processing is impaired by large amounts of non-painrelated activity
Missing linkers : an alternative pathway to UiO-66 electronic structure engineering
UiO-66 is a promising metal-organic framework for photocatalytic applications. However, the ligand-to-metal charge transfer of an excited electron is inefficient in the pristine material. Herein, we assess the influence of missing linker defects on the electronic structure of UiO-66 and discuss their ability to improve ligand-to-metal charge transfer. Using a new defect classification system, which is transparent and easily extendable, we identify the most promising photocatalysts by considering both relative stability and electronic structure. We find that the properties of UiO-66 defect structures largely depend on the coordination of the constituent nodes and that the nodes with the strongest local distortions alter the electronic structure most. Defects hence provide an alternative pathway to tune UiO-66 for photocatalytic purposes, besides linker modification and node metal substitution. In addition, the decomposition of MOF properties into node- and linker-based behavior is more generally valid, so we propose orthogonal electronic structure tuning as a paradigm in MOF design
Influence of spray drying suspension on the morphology of Fe-based oxygen carriers for chemical looping
Chemical looping reforming (CLR) and chemical looping combustion (CLC) are promising technologies with inherent CO2 capture for transforming fuels into syngas and energy respectively. Circulating oxygen carriers (OC) are used to transfer oxygen from mostly air to the fuel inside the process. Over the past years a variety of materials have been proposed for the role of oxygen carriers, ranging from bulk mineral powders to oxygen carrier particles engineered for shape, size and composition. Iron based materials are very promising and cost effective candidates with minor impact on the environment as compared to the toxic Ni-based OCs.
Granulation by the industrial spray-drying technique is suitable for producing oxygen carrier particles with high sphericity and dimensions fit for the fluidized-bed reactors of the CL-process. The lifetime of the oxygen carriers in these reactors however strongly depends on their mechanical properties (as measured by the crushing strength and the attrition resistance) which is related with their morphology and porosity. As this morphology depends on the spray drying suspension, the relation between the additives used in the iron-based suspension and the morphology of the spray-dried particles is investigated in this work [1]. The influence of the concentration of the binder, dispersing agent and solids in the spray-drying suspensions and the intensity of the milling procedure on the morphology and microstructure of the resulting particles is studied by Hg-porosimetry, tapped density, optical microscopy and SEM. A controlled sintering treatment is used during post-processing of these spray-dried particles in order to further improve their mechanical properties before investigating their performance as oxygen carriers in the chemical looping process
Divergent roles of CprK paralogues from Desulfitobacterium hafniense in activating gene expression
Gene duplication and horizontal gene transfer play an important role in the evolution of prokaryotic genomes. We have investigated the role of three CprK paralogues from the cAMP receptor protein-fumarate and nitrate reduction regulator (CRP-FNR) family of transcriptional regulators that are encoded in the genome of Desulfitobacterium hafniense DCB-2 and possibly regulate expression of genes involved in the energy-conserving terminal reduction of organohalides (halorespiration). The results from in vivo and in vitro promoter probe assays show that two regulators (CprK1 and CprK2) have an at least partially overlapping effector specificity, with preference for ortho-chlorophenols, while meta-chlorophenols proved to be effectors for CprK4. The presence of a potential transposase-encoding gene in the vicinity of the cprK genes indicates that their redundancy is probably caused by mobile genetic elements. The CprK paralogues activated transcription from promoters containing a 14 bp inverted repeat (dehalobox) that closely resembles the FNR-box. We found a strong negative correlation between the rate of transcriptional activation and the number of nuclecitide changes from the optimal dehalobox sequence (TTAAT-N-4-ATTAA). Transcription was initiated by CprK4 from a promoter that is situated upstream of a gene encoding a methyl-accepting chemotaxis protein. This might be the first indication of taxis of an anaerobic bacterium to halogenated aromatic compounds
A Linguistic Research Programme for Reading in African Languages to underpin CAPS
Although ANAs show language conditioned problems in reading comprehension and decoding ability, most South African research focuses disproportionately on (a) English and Afrikaans and (b) macro approaches to literacy rather than formal and psycholinguistic analyses of reading. Obviously African languages are structurally and typologically different to English and Afrikaans; reading strategies required for the mechanics of reading are necessarily different and should be supported by language-specific pedagogies. We argue for research programmes that situate reading pedagogy within the language-specific spaces defined by Linguistic approaches to understanding (a) orthography, (b) cognitive reading skills and models and (c) indigenous, language-specific norms and resources.Keywords: psycholinguistics, linguistics, orthography, morphological awareness, phonological awareness, curriculum developmen
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