| 351. |
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| 352. |
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| 353. |
- Wuttke, Matthias, et al.
(författare)
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A catalog of genetic loci associated with kidney function from analyses of a million individuals
- 2019
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Ingår i: Nature Genetics. - : NATURE PUBLISHING GROUP. - 1061-4036 .- 1546-1718. ; 51:6, s. 957-972
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Tidskriftsartikel (refereegranskat)abstract
- Chronic kidney disease (CKD) is responsible for a public health burden with multi-systemic complications. Through transancestry meta-analysis of genome-wide association studies of estimated glomerular filtration rate (eGFR) and independent replication (n = 1,046,070), we identified 264 associated loci (166 new). Of these,147 were likely to be relevant for kidney function on the basis of associations with the alternative kidney function marker blood urea nitrogen (n = 416,178). Pathway and enrichment analyses, including mouse models with renal phenotypes, support the kidney as the main target organ. A genetic risk score for lower eGFR was associated with clinically diagnosed CKD in 452,264 independent individuals. Colocalization analyses of associations with eGFR among 783,978 European-ancestry individuals and gene expression across 46 human tissues, including tubulo-interstitial and glomerular kidney compartments, identified 17 genes differentially expressed in kidney. Fine-mapping highlighted missense driver variants in 11 genes and kidney-specific regulatory variants. These results provide a comprehensive priority list of molecular targets for translational research.
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| 354. |
- Yohannes, T., et al.
(författare)
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Polyfluorene copolymer based bulk heterojunction solar cells
- 2004
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Ingår i: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 449:1-2, s. 152-157
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Tidskriftsartikel (refereegranskat)abstract
- Bulk heterojunction solar cells based on blends of photoactive layers of polyfluorene copolymer Poly((2,7-(9-(2'-ethylhexyl)-9-hexyl-fluorene)-alt-5,5-(4', 7'-di-2-thienyl-2',1',3'-benzothiadiazole))-co-(2, 7-(9-(2'-ethylhexyl)-9-hexyl-fluorene)-alt-2,5-thiophene)) (LBPF3) acting as electron donor, and [6,6]-phenyl-C61-butyric acid methylester (PCBM), acting as electron acceptor, were constructed and studied. The power conversion efficiency for a 1:4 (by weight) blend of LBPF3:PCBM under simulated solar light illumination having light intensity of 100 mW/cm2 was 1.7%, and 9.2% under monochromatic (565 nm) light illumination with light intensity of 0.145 mW/cm2. The maximum external quantum efficiency (incident photons to converted electrons) for this device was found to be above 40% from 400 to 560 nm. The effects of blend composition and film thickness on the photovoltaic parameters were also studied. The incident light intensity dependence of the short circuit current showed a linear relationship. © 2003 Elsevier B.V. All rights reserved.
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| 355. |
- Zhang, Chaofan, et al.
(författare)
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Core-shell structure in self-assembled lead/lead-oxide nanoclusters revealed by photoelectron spectroscopy
- 2013
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Institute of Physics (AIP). - 1098-0121 .- 1550-235X. ; 87:3, s. 035402-
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Tidskriftsartikel (refereegranskat)abstract
- Nanoclusters containing metallic lead and lead oxide have been produced by self-assembly out of a primary mixture of lead atoms and oxygen in a reactive sputtering-based cluster source. Comparison of the valence and core-level responses in the photoelectron spectra shows that clusters have a core-shell structure with a lead-oxide core coated by an outer shell of metallic lead. This core-shell order is opposite to that typical for most microscopic and macroscopic materials. We explain this by the peculiarities of the cluster production kinetics and by the system's energy minimization striving due to what lead oxide is placed in the core of the mixed cluster.
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| 356. |
- Zhang, Chaofan, et al.
(författare)
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Holding onto Electrons in Alkali Metal Halide Clusters : Decreasing Polarizability with Increasing Coordination
- 2012
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 116:49, s. 12104-12111
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Tidskriftsartikel (refereegranskat)abstract
- The connection between the electronic polarizability and the decrease of the system size from macroscopic solid to nanoscale clusters has been addressed in a combined experimental and model-calculation study. A beam of free neutral potassium chloride clusters has been probed using synchrotron-radiation-based photoelectron spectroscopy. The introduction of "effective" polarizability for chlorine, lower than that in molecules and dimers and decreasing with increasing coordination, has allowed us to significantly improve the agreement between the experimental electron binding energies and the electrostatic model predictions. Using the calculated site-specific binding energies, we have been able to assign the spectral details of the cluster response to the ionizing X-ray radiation, and to explain its change with cluster size. From our assignments we find that the higher-coordination face-atom responses in the K 3p spectra increase significantly with increasing cluster size relative to that of the edge atoms. The reasons behind the decrease of polarizability predicted earlier by ab initio calculations are discussed in terms of the limited mobility of the electron clouds caused by the interaction with the neighboring ions.
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| 357. |
- Zhang, Chaofan, et al.
(författare)
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Ionic bonding in free nanoscale NaCl clusters as seen by photoelectron spectroscopy
- 2011
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 134:12, s. 124507-
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Tidskriftsartikel (refereegranskat)abstract
- The free neutral nanoscale NaCl clusters have been produced in a beam and studied with x-ray photoelectron spectroscopy. High resolution spectra simultaneously containing cluster and molecular-monomer, featuring in both the valence and core-level Na 2p and Cl 2p regions, have been obtained. Cluster-level energy shifts of around 3 eV toward lower binding energy for Na 2p and approximate to 1 eV toward higher binding energy for Cl 2p relative to the monomer levels have been unambiguously established. To rationalize the core-level energy shifts of the nanoscale NaCl clusters, the ionic model taking into account all charge-charge and polarization interactions has been developed and implemented. A satisfactory agreement between the experimental and model results has been obtained. The model calculations have also shed additional light on the size-and site-specific cluster responses.
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| 358. |
- Zhang, Chaofan
(författare)
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Multicomponent Clusters/Nanoparticles : An Investigation of Electronic and Geometric Properties by Photoelectron Spectroscopy
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Clusters/nanoparticles are aggregates of a “small” number of building blocks, atoms or molecules, ranging from two up to millions of atoms. Two main groups of clusters have been studied using photoelectron spectroscopy based on synchrotron radiation. They are dry/wet alkali-halide clusters, including pure water clusters, and metal-based nanoparticles.For the dry alkali halide clusters, analysis of the data and theoretical modeling has allowed us insights into the local electronic properties at nanoscale: a change of polarizability of ions in the alkali-halide clusters due to the varying environment has been suggested. The study of the wet salt clusters shows that the alkali-halides are already solvated at the nanoscale reached by water clusters doped with salt vapor.The photoelectron angular distribution of water cluster shows lower anisotropy parameters as compared to the separate monomers. A model based on intracluster scattering has been built to partly explain the reduction.In the last part of the thesis, metal-based multi-component nanoparticles have been produced by self-assembly processes using reactive magnetron sputtering. Depending on the specific metal element, oxidation processes have been applied before or after the aggregation. Clearly radial distributions such as core-shell and “sandwich-like” structures have unambiguously determined by photoelectron spectroscopy.
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| 359. |
- Zhang, Fengling, et al.
(författare)
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Influence of buffer layers on the performance of polymer solar cells
- 2004
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 84:19, s. 3906-3908
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Tidskriftsartikel (refereegranskat)abstract
- The study of the influence of different anode buffer layers on the performance of solar cells based on blends of polyfluorene copolymers, acting as electron donor, and [6,6]-phenyl-C61-butyric acid methylester (PCBM), acting as electron acceptor was presented. The construction of buffer later was done from different forms of poly(3, 4-ethylenedioxythiophene) poly-(styrenesulfonate) (PEDOT-PSS). Variations in open-circuit voltage, short-circuit current and fill factor were also observed. The anode buffer layer influences the photovoltage of polymer solar cells by controlling the conditions for charge injection at the anode.
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| 360. |
- Zhang, Fengling, et al.
(författare)
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Influence of solvent mixing on the morphology and performance of solar cells based on polyfluorene copolymer/fullerene blends
- 2006
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 16:5, s. 667-674
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the solvent on the morphol. and performance of polymer solar cells was studied in devices based on blends of the polyfluorene copolymer, poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2-thienyl-2', 1',3'-benzothiadiazole)), and [6,6]-phenyl-C61-butyric acid Me ester. The blends are spin-coated from CHCl3 or from CHCl3 mixed with small amts. of xylene, toluene, or chlorobenzene. The devices are characterized under monochromatic light and AM1.5 solar illumination. An enhancement of the photocurrent d. was obsd. in diodes made from CHCl3 mixed with chlorobenzene, and a decreased photocurrent d. is obsd. in diodes made from CHCl3 mixed with xylene or toluene, compared to diodes made from neat CHCl3. The open-circuit voltages are almost the same for all diodes. The surfaces of the active layers were imaged with AFM. Height images indicate that a finer and more uniform distribution of domains corresponds to the diodes with enhanced photocurrent that are made from CHCl3 mixed with chlorobenzene, while a structure with larger domains is assocd. with the lower photocurrents in the diodes made from CHCl3 mixed with xylene or toluene. The influence of the morphol. on the excited-state dynamics and charge generation was studied using time-resolved spectroscopy. Fast formation of bound charge pairs followed by their conversion into free charge carriers was resolved, and excitation-intensity-dependent non-geminate recombination of free charges was obsd. A significant enhancement in free-charge-carrier generation was obsd. on introducing chlorobenzene into CHCl3. Imaging photocurrent generation from the solar cells with a light-pulse technique shows an inhomogeneous photocurrent distribution, which is related to the undulations in the thickness of the active layer. Thicker parts of the diodes yield higher photocurrent values. [on SciFinder (R)]
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