2,177 research outputs found

    Rationeel onkruidbeheer op verhardingen

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    Verslag van een workshop over duurzaam onkruidbeheer op verhardingen. Belangrijkste thema's waren afspoeling van herbiciden en kosten-effectief onkruidbehee

    Blind Inversion of Wiener Systems

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    A system in which a linear dynamic part is followed by a non linear memoryless distortion a Wiener system is blindly inverted This kind of systems can be modelised as a postnonlinear mixture and using some results about these mixtures an e cient algorithm is proposed Results in a hard situation are presented and illustrate the e ciency of this algorith

    Integrated microfluidic biosensing platform for simultaneous confocal microscopy and electrophysiological measurements on bilayer lipid membranes and ion channels

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    Combining high-resolution imaging and electrophysiological recordings is key for various types of experimentation on lipid bilayers and ion channels. Here, we propose an integrated biosensing platform consisting of a microfluidic cartridge and a dedicated chip-holder to conduct such dual measurements on suspended lipid bilayers, in a user-friendly manner. To illustrate the potential of the integrated platform, we characterize lipid bilayers in terms of thickness and fluidity while simultaneously monitoring single ion channel currents. For that purpose, POPC lipid bilayers are supplemented with a fluorescently-tagged phospholipid (NBD-PE, 1% mol) for Fluorescence Recovery After Photobleaching (FRAP) measurements and a model ion channel (gramicidin, 1 nM). These combined measurements reveal that NBD-PE has no effect on the lipid bilayer thickness while gramicidin induces thinning of the membrane. Furthermore, the presence of gramicidin does not alter the lipid bilayer fluidity. Surprisingly, in lipid bilayers supplemented with both probes, a reduction in gramicidin open probability and lifetime is observed compared to lipid bilayers with gramicidin only, suggesting an influence of NBD-PE on the gramicidin ion function. Altogether, our proposed microfluidic biosensing platform in combination with the herein presented multi-parametric measurement scheme paves the way to explore the interdependent relationship between lipid bilayer properties and ion channel function

    Modular ATR FT-IR microreactor chip for optimizing reaction conditions

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    A silicon chip for attenuated total reflection (ATR) Fourier transform infrared (FT-IR) spectroscopy in combination with a modular PDMS herringbone mixer and a microreactor has been successfully fabricated and tested. The modular design allows the chip to be used for a variety of reactions. A model synthesis of 1-butyl-2,5-dimethyl-1H-pyrrole from hexane-2,5-dione with 1-butylamine has been performed on chip. When plotting the natural logarithm of the peak area corresponding to the ketone stretch vibration at 1710cm-1, against the residence time, a linear curve can be fitted, suggesting this step to be a first order reaction

    Modular ATR FT-IR microreactor chip for optimizing reaction conditions

    Get PDF
    A silicon chip for attenuated total reflection (ATR) Fourier transform infrared (FT-IR) spectroscopy in combination with a modular PDMS herringbone mixer and a microreactor has been successfully fabricated and tested. The modular design allows the chip to be used for a variety of reactions. A model synthesis of 1-butyl-2,5-dimethyl-1H-pyrrole from hexane-2,5-dione with 1-butylamine has been performed on chip. When plotting the natural logarithm of the peak area corresponding to the ketone stretch vibration at 1710cm-1, against the residence time, a linear curve can be fitted, suggesting this step to be a first order reaction

    Targeted treatment options for paediatric B-cell precursor acute lymphoblastic leukaemia patients with constitutional or somatic chromosome 21 alterations

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    Background: Chromosome 21 is affected in ∼60% of paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) patients and includes somatic and constitutional gains, intrachromosomal amplification of chromosome 21 (iAMP21), and the translocation t(12;21) resulting in the ETV6::RUNX1 gene fusion. Methods: Since these numeric and structural chromosome 21 alterations are not targetable, we studied the type and frequency of yet-proven targetable events co-occurring with chromosome 21 alterations.Results: Among 307 primary paediatric BCP-ALL cases, JAK/STAT pathway lesions were most frequent in patients with constitutional gain of chromosome 21 (Down syndrome ALL; 35/71, 49%) and iAMP21 (9/22, 41%). RAS pathway lesions were most frequent in high hyperdiploidy (62/108, 57%) and FLT3 lesions were most frequent in iAMP21 (7/22, 32%). Virtually all cases expressed CD19 and CD22 at the cell surface. Positivity for CD20 surface expression ranged from 67% in iAMP21 (8/12) to 20% in ETV6::RUNX1 (26/129). Conclusion: Activated JAK/STAT, RAS or FLT3 signalling, and CD marker surface expression may provide targetable treatment options for the majority of chromosome 21-altered BCP-ALL cases.</p

    Improved stability regions for ground states of the extended Hubbard model

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    The ground state phase diagram of the extended Hubbard model containing nearest and next-to-nearest neighbor interactions is investigated in the thermodynamic limit using an exact method. It is found that taking into account local correlations and adding next-to-nearest neighbor interactions both have significant effects on the position of the phase boundaries. Improved stability domains for the η\eta-pairing state and for the fully saturated ferromagnetic state at half filling have been constructed. The results show that these states are the ground states for model Hamiltonians with realistic values of the interaction parameters.Comment: 21 pages (10 figures are included) Revtex, revised version. To be published in Phys. Rev. B. E-mail: [email protected]

    Addition of the FTD Module to the Neuropsychiatric Inventory improves classification of frontotemporal dementia spectrum disorders

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    Most neuropsychiatric symptoms (NPS) common in frontotemporal dementia (FTD) are currently not part of the Neuropsychiatric Inventory (NPI). We piloted an FTD Module that included eight extra items to be used in conjunction with the NPI. Caregivers of patients with behavioural variant FTD (n = 49), primary progressive aphasia (PPA; n = 52), Alzheimer's dementia (AD; n = 41), psychiatric disorders (n = 18), presymptomatic mutation carriers (n = 58) and controls (n = 58) completed the NPI and FTD Module. We investigated (concurrent and construct) validity, factor structure and internal consistency of the NPI and FTD Module. We performed group comparisons on item prevalence, mean item and total NPI and NPI with FTD Module scores, and multinomial logistic regression to determine its classification abilities. We extracted four components, together explaining 64.1% of the total variance, of which the largest indicated the underlying dimension 'frontal-behavioural symptoms'. Whilst apathy (original NPI) occurred most frequently in AD, logopenic and non-fluent variant PPA, the most common NPS in behavioural variant FTD and semantic variant PPA were loss of sympathy/empathy and poor response to social/emotional cues (part of FTD Module). Patients with primary psychiatric disorders and behavioural variant FTD showed the most severe behavioural problems on both the NPI as well as the NPI with FTD Module. The NPI with FTD Module correctly classified more FTD patients than the NPI alone. By quantifying common NPS in FTD the NPI with FTD Module has large diagnostic potential. Future studies should investigate whether it can also prove a useful addition to the NPI in therapeutic trials
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