| 1. |
- Wang, Yuhang, et al.
(författare)
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Purification and characterization of recombinant human bile salt-stimulated lipase expressed in milk of transgenic cloned cows
- 2017
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Bile salt-stimulated lipase (BSSL) is a lipolytic digestive enzyme with broad substrate specificity secreted from exocrine pancreas into the intestinal lumen in all species and from the lactating mammary gland into the milk of some species, notably humans but not cows. BSSL in breast milk facilitates digestion and absorption of milk fat and promotes growth of small for gestational age preterm infants. Thus, purified recombinant human BSSL (rhBSSL) can be used for treatment of patients with fat malabsorption and expressing rhBSSL in the milk of transgenic cloned cows would therefore be a mean to meet a medical need. In the present study, a vector pBAC-hLF-hBSSL was constructed, which efficiently expressed active rhBSSL in milk of transgenic cloned cows to a concentration of 9.8 mg/ml. The rhBSSL purified from cow milk had the same enzymatic activity, N-terminal amino acid sequence, amino acid composition and isoelectric point and similar physicochemical characteristics as human native BSSL. Our study supports the use of transgenic cattle for the cost-competitive, large-scale production of therapeutic rhBSSL.
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| 2. |
- Wang, Haibin, et al.
(författare)
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Strain in Copper/Ceria Heterostructure Promotes Electrosynthesis of Multicarbon Products
- 2023
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Ingår i: ACS Nano. - : American Chemical Society. - 1936-0851 .- 1936-086X. ; 17:1, s. 346-354
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Tidskriftsartikel (refereegranskat)abstract
- Elastic strains in metallic catalysts induce enhanced selectivity for carbon dioxide reduction (CO2R) toward valuable multicarbon (C2+) products. However, under working conditions, the structure of catalysts inevitably undergoes reconstruction, hardly retaining the initial strain. Herein, we present a metal/metal oxide synthetic strategy to introduce and maintain the tensile strain in a copper/ceria heterostructure, enabled by the presence of a thin interface layer of Cu2O/CeO2. The tensile strain in the copper domain and deficient electron environment around interfacial Cu sites resulted in strengthened adsorption of carbonaceous intermediates and promoted*CO dimerization. The strain effect in the copper/ceria heterostructure leads to an improved C2+ selectivity with a maximum Faradaic efficiency of 76.4% and a half-cell power conversion efficiency of 49.1%. The fundamental insights gained from this system can facilitate the rational design of heterostructure catalysts for CO2R.
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| 3. |
- Hong, Li, et al.
(författare)
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Thiocyanate-Mediated Dimensionality Transformation of Low- Dimensional Perovskites for Photovoltaics
- 2022
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 34:14, s. 6331-6338
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Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional (2D) hybrid perovskite solar cells have induced widespread research interest owing to their higher stability as compared to three-dimensional (3D) analogues. The photovoltaic performance, however, is still limited. Here, we report a perovskite film dominated by 3D components that are modulated by formamidinium thiocyanate in the 2D PEA(2)FA(3)Pb(4)I(13) perovskite composition. We demonstrate that a dimensionality transformation from a 2D/3D to predominantly 3D perovskite phase in the presence of SCN-based treatment enhances the optical absorption in visible and near-infrared regions. As a result, the power conversion efficiency improved 4.5 times with respect to the control to above 14%. The unencapsulated cell exhibited excellent moisture stability during the shelf lifetime measurement over 70 days under ambient conditions.
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| 4. |
- Shao, Zicheng, et al.
(författare)
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Effect of Sr Substitution on the Novel la 1-xSr xCo0.5Ni0.5O3- δPerovskite-Type Catalysts for Hydrogen Production in Ethanol Steam Reforming
- 2023
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Ingår i: International Journal of Energy Research. - : Hindawi Limited. - 0363-907X .- 1099-114X. ; 2023
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Tidskriftsartikel (refereegranskat)abstract
- La1-xSrxCo0.5Ni0.5O3-δ perovskites with different substitution of La by Sr have been firstly synthesized and applied as catalysts for ethanol steam reforming (ESR). The effect of partial Sr substitution on the performance and stability of La1-xSrxCo0.5Ni0.5O3-δ for ESR was investigated. The synthesized samples were characterized by XRD, SEM, BET, and EDS techniques. The results show that with the increase of substitution of La by Sr, the pore size and surface area of La1-xSrxCo0.5Ni0.5O3-δ perovskite increase. The doping of Sr causes changes in the specific surface area, pore volume, and pore size of the catalyst, which in turn causes changes in its catalytic activity. Meanwhile, La0.1Sr0.9Co0.5Ni0.5O3-δ with a highest SBET presents the highest ethanol conversion rate among all the samples. The modifications of catalyst characteristics caused by the Sr substitution in La1-xSrxCo0.5Ni0.5O3-δ directly affect its catalytic performance in the ESR. What is more, the influences of operating parameters on the catalytic activity of La0.1Sr0.9Co0.5Ni0.5O3-δ were studied in detail, and the optimum conditions were determined and applied for stability experiments. When the temperature is lower than 500°C, the selectivity of gas products is most likely affected by the dehydrogenation of ethanol and the decomposition of acetaldehyde. Meanwhile, the improving hydrogen selectivity and reducing the formation of by-products can be achieved by increasing the reaction temperature. The best catalytic performance for hydrogen production was achieved with La0.1Sr0.9Co0.5Ni0.5O3-δ which presented the highest ethanol conversion (98.7%) under the optimal reaction conditions. La0.1Sr0.9Co0.5Ni0.5O3-δ perovskites with higher strontium degree of substitution exhibited an excellent activity and stability of the catalysts derived.
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| 5. |
- Shen, Qiuwan, et al.
(författare)
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Synthesis and experimental study of improved double perovskite-type PrBaCo2O5+δ materials to produce oxygen-enriched CO2 for oxyfuel combustion application
- 2022
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Ingår i: Journal of Ceramic Processing Research. - 1229-9162. ; 23:5, s. 611-616
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite oxides are promising oxygen carrier materials to produce O2/CO2 gas for oxyfuel combustion application. In this study, PrBaCo2O5+δ double perovskite oxide was prepared by the EDTA sol-gel method and first applied as oxygen carrier for oxygen production. The oxygen adsorption/desorption performance of PrBaCo2O5+δ perovskite was carrried out in a fixed-bed set-up. The operating factors of oxygen releasing performance were investigated in detail including adsorption temperature, desorption temperature, CO2 volumetric flow rate, and CO2 partial pressure. Due to the kinetic effects of gas-solid reactions, it is found that the adsorption and desorption temperature has greatly influence on the oxygen production performance. The surface morphology was observed by scanning electron microscope (SEM). In addition, the cyclic performance of PrBaCo2O5+δ under the optimal operating condition was examined. The oxygen production amount was reduced slightly from 110.9 mg/g perovskite to 99.2 mg/g after 8 cycles’ test. Therefore, the results indicated that PrBaCo2O5+δ has good stability and reactivity for cyclic use.
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| 6. |
- Shen, Qiuwan, et al.
(författare)
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Synthesis and experimental study of novel double perovskite Ba2NixCo2−xO6 as promising oxygen carrier materials for CO2 capture application
- 2020
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Ingår i: International Journal of Energy Research. - : Hindawi Limited. - 0363-907X .- 1099-114X. ; 44:8, s. 6991-6999
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Tidskriftsartikel (refereegranskat)abstract
- Novel oxygen-deficient double-perovskite type oxide Ba2NixCo2−xO6 was applied to produce O2/CO2 mixed stream gas for oxyfuel combustion application. A series of different Co concentration substituted Ba2NixCo2−xO6 was synthesized by an EDTA-citrate sol-gel combustion method. The oxygen carriers, Ba2Ni0.25Co1.75O6, Ba2Ni0.45Co1.55O6, Ba2Ni0.65Co1.35O6 and Ba2Ni0.85Co1.15O6 were c\characterized by scanning electron microscopy and cyclic oxygen adsorption/desorption experiments. The results showed that the capacity of provided O2 was improved by the partial substitution of Ni by Co. In addition, the synthesized perovskites exhibit good regeneration ability. The optimal degree of Co substitution was x = 0.25 for Ba2NixCo2−xO6 with consideration of oxygen desorption ability. Therefore, Ba2Ni0.25Co1.75O6 was selected to examine the influence of the operating parameters on the oxygen release performance. It was found that the desorption temperature and CO2 partial pressure are the two main operating parameters for the oxygen desorption performance. Further, the proposed novel double perovskite Ba2Ni0.25Co1.75O6 provided excellent performance, the O2 production of Ba2Ni0.25Co1.75O6 can still reach 120 mg/g after 10 cycles.
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| 7. |
- Van den Berg, Ronald, et al.
(författare)
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No effect of monetary reward in a visual working memory task
- 2023
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- Previous work has shown that humans distribute their visual working memory (VWM) resources flexibly across items: the higher the importance of an item, the better it is remembered. A related, but much less studied question is whether people also have control over the totalamount of VWM resource allocated to a task. Here, we approach this question by testing whether increasing monetary incentives results in better overall VWM performance. In three experiments, subjects performed a delayed-estimation task on the Amazon Turk platform. In the first two experiments, four groups of subjects received a bonus payment based on their performance, with the maximum bonus ranging from $0 to $10 between groups. We found no effect of the amount of bonus on intrinsic motivation or on VWM performance in either experiment. In the third experiment, reward was manipulated on a trial-by-trial basis using a within-subjects design. Again, no evidence was found that VWM performance depended on the magnitude of potential reward. These results suggest that encoding quality in visual working memory is insensitive to monetary reward, which has implications for resource-rational theories of VWM.
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| 8. |
- Yu, Huakang, et al.
(författare)
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Modeling bending losses of optical nanofibers or nanowires
- 2009
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Ingår i: Applied Optics. - 1559-128X .- 2155-3165. ; 48:22, s. 4365-4369
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Tidskriftsartikel (refereegranskat)abstract
- Bending losses of nanofibers or nanowires with circular 90 degrees bends are simulated using a three-dimensional finite-difference time-domain (3D-FDTD) method. Dependences of bending losses on wavelength and polarization of guided light are investigated, as well as the diameters, refractive indices, and bending radii of nanowires. The acceptable bending losses (similar to 1 dB/90 degrees) predicted in glass, polymer, and semiconductor nanowires with bending radii down to micrometer level may offer valuable references for assembling highly compact photonic integrated circuits or devices with optical nanowires.
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