| 1. |
- Borel, Cédric, 1979, et al.
(författare)
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Family of Isoreticular Chiral Metal-Organic Frameworks Based on Coordination and Hydrogen Bonds in [M[Co(ethylenediamine)(oxalato)2]2]
- 2010
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 10:4, s. 1971-1978
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Tidskriftsartikel (refereegranskat)abstract
- From the parent compound [Ca[Co(ethylenediamine)(oxalato)2]2]n . 4H2O, 1, a series of framework compounds was prepared via the soluble sodium salt and crystal growth with the divalent metal ions Cd2+, Mn2+, and Sr2+, (2-4). These compounds have the same general formula [M[Co(ethylenediamine)(oxalato)2]2]n . xH2O, and they all form the same four- and eight-connected 3D net having scu topology (and are thus isoreticular) with water filled channels of variable size running in one direction of the crystals. However, they crystallize in two different space groups, the chiral P21) (3, 4, and the low temperature form of 1) and the noncentrosymmetric P-4 (1 and 2). The potential voids upon water removal are 18-20% of the unit cell. Preliminary gas sorption measurements at 298 K and 8 bar show substantial CO2 and N2O uptake (12-14% and 15-16% by mass, respectively), while the H2 uptake was 0.18%, a relatively high value considering the low pressure and high temperature.
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| 2. |
- Langer, Dominik, et al.
(författare)
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HelioScan : A software framework for controlling in vivo microscopy setups with high hardware flexibility, functional diversity and extendibility
- 2013
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Ingår i: Journal of Neuroscience Methods. - : Elsevier BV. - 0165-0270 .- 1872-678X. ; 215:1, s. 38-52
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Tidskriftsartikel (refereegranskat)abstract
- Intravital microscopy such as in vivo imaging of brain dynamics is often performed with custom-built microscope setups controlled by custom-written software to meet specific requirements. Continuous technological advancement in the field has created a need for new control software that is flexible enough to support the biological researcher with innovative imaging techniques and provide the developer with a solid platform for quickly and easily implementing new extensions. Here, we introduce HelioScan, a software package written in LabVIEW, as a platform serving this dual role. HelioScan is designed as a collection of components that can be flexibly assembled into microscope control software tailored to the particular hardware and functionality requirements. Moreover, HelioScan provides a software framework, within which new functionality can be implemented in a quick and structured manner. A specific HelioScan application assembles at run-time from individual software components, based on user-definable configuration files. Due to its component-based architecture, HelioScan can exploit synergies of multiple developers working in parallel on different components in a community effort. We exemplify the capabilities and versatility of HelioScan by demonstrating several in vivo brain imaging modes, including camera-based intrinsic optical signal imaging for functional mapping of cortical areas, standard two-photon laser-scanning microscopy using galvanometric mirrors, and high-speed in vivo two-photon calcium imaging using either acousto-optic deflectors or a resonant scanner. We recommend HelioScan as a convenient software framework for the in vivo imaging community.
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| 3. |
- Müllauer, Julia, et al.
(författare)
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Pharmacokinetic modeling of P-glycoprotein function at the rat and human blood--brain barriers studied with (R)-[11C]verapamil positron emission tomography.
- 2012
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Ingår i: EJNMMI Research. - 2191-219X. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: This study investigated the influence of P-glycoprotein (P-gp) inhibitor tariquidar on the pharmacokinetics of P-gp substrate radiotracer (R)-[11C]verapamil in plasma and brain of rats and humans by means of positron emission tomography (PET). METHODS: Data obtained from a preclinical and clinical study, in which paired (R)-[11C]verapamil PET scans were performed before, during, and after tariquidar administration, were analyzed using nonlinear mixed effects (NLME) modeling. Administration of tariquidar was included as a covariate on the influx and efflux parameters (Qin and Qout) in order to investigate if tariquidar increased influx or decreased outflux of radiotracer across the blood--brain barrier (BBB). Additionally, the influence of pilocarpine-induced status epilepticus (SE) was tested on all model parameters, and the brain-to-plasma partition coefficient (VT-NLME) was calculated. RESULTS: Our model indicated that tariquidar enhances brain uptake of (R)-[11C]verapamil by decreasing Qout. The reduction in Qout in rats during and immediately after tariquidar administration (sevenfold) was more pronounced than in the second PET scan acquired 2 h after tariquidar administration (fivefold). The effect of tariquidar on Qout in humans was apparent during and immediately after tariquidar administration (twofold reduction in Qout) but was negligible in the second PET scan. SE was found to influence the pharmacological volume of distribution of the central brain compartment Vbr1. Tariquidar treatment lead to an increase in VT-NLME, and pilocarpine-induced SE lead to increased (R)-[11C]verapamil distribution to the peripheral brain compartment. CONCLUSIONS: Using NLME modeling, we were able to provide mechanistic insight into the effects of tariquidar and SE on (R)-[11C]verapamil transport across the BBB in control and 48 h post SE rats as well as in humans.
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| 4. |
- van Assema, Danielle M. E., et al.
(författare)
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Blood-brain barrier P-glycoprotein function in Alzheimer's disease
- 2012
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 135, s. 181-189
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Tidskriftsartikel (refereegranskat)abstract
- A major pathological hallmark of Alzheimer's disease is accumulation of amyloid-beta in senile plaques in the brain. Evidence is accumulating that decreased clearance of amyloid-beta from the brain may lead to these elevated amyloid-beta levels. One of the clearance pathways of amyloid-beta is transport across the blood-brain barrier via efflux transporters. P-glycoprotein, an efflux pump highly expressed at the endothelial cells of the blood-brain barrier, has been shown to transport amyloid-beta. P-glycoprotein function can be assessed in vivo using (R)-[C-11]verapamil and positron emission tomography. The aim of this study was to assess blood-brain barrier P-glycoprotein function in patients with Alzheimer's disease compared with age-matched healthy controls using (R)-[C-11]verapamil and positron emission tomography. In 13 patients with Alzheimer's disease (age 65 +/- 7 years, Mini-Mental State Examination 23 +/- 3), global (R)-[C-11]verapamil binding potential values were increased significantly (P = 0.001) compared with 14 healthy controls (aged 62 +/- 4 years, Mini-Mental State Examination 30 +/- 1). Global (R)-[C-11]verapamil binding potential values were 2.18 +/- 0.25 for patients with Alzheimer's disease and 1.77 +/- 0.41 for healthy controls. In patients with Alzheimer's disease, higher (R)-[C-11]verapamil binding potential values were found for frontal, parietal, temporal and occipital cortices, and posterior and anterior cingulate. No significant differences between groups were found for medial temporal lobe and cerebellum. These data show altered kinetics of (R)-[C-11]verapamil in Alzheimer's disease, similar to alterations seen in studies where P-glycoprotein is blocked by a pharmacological agent. As such, these data indicate that P-glycoprotein function is decreased in patients with Alzheimer's disease. This is the first direct evidence that the P-glycoprotein transporter at the blood-brain barrier is compromised in sporadic Alzheimer's disease and suggests that decreased P-glycoprotein function may be involved in the pathogenesis of Alzheimer's disease.
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