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91.
Companies have long used various approaches for organizing their employees' time for creative and routine tasks in order to improve innovative performance. In this paper, we examine how work schedule autonomy affects individuals' creative and routine performance. We then evaluate non‐commissioned time models. Results of laboratory experiments with 233 participants reveal that while average routine performance is not affected by schedule autonomy, the effect of schedule autonomy on creative performance depends on the subject's impulsiveness. There is evidence of an inverse relationship between schedule autonomy and creative performance among subjects of low impulsiveness. Hence, our results indicate that the optimal management policy depends on the manager's focus on creative or routine performance and the types of employees the manager supervises. For routine performance, the creativity time model has no significant impact. 相似文献
92.
Guo‐Feng Luo Yonatan Biniuri Margarita Vzquez‐Gonzlez Verena Wulf Michael Fadeev Ronit Lavi Itamar Willner 《Advanced functional materials》2019,29(33)
A series of metal ion‐terpyridine‐modified L‐tyrosinamide aptamers (Mn + = Cu2+ or Fe3+) act as enzyme‐mimicking catalysts (nucleoapzymes) for oxygen‐insertion into C? H bonds and the transformation of L‐tyrosinamide into amidodopachrome. The reaction proceeds in the presence of H2O2 and coadded L‐ascorbic acid. In one series of experiments, the catalyzed oxidation of L‐tyrosinamide to amidodopachrome by a set of nucleoapzymes consisting of Fe3+‐ or Cu2+‐terpyridine complexes tethered directly or through a 4 × thymidine (4 × T) bridge, to the 5′‐ or 3′‐end of the 49‐mer L‐tyrosinamide aptamer or to a shorter 23‐mer L‐tyrosinamide aptamer is examined. All nucleoapzymes reveal catalytic Michaelis–Menten enzyme‐like activities and the separated Fe3+‐ or Cu2+‐terpyridine and L‐tyrosinamide aptamer units show only minute catalytic properties. The catalytic activities of the nucleoapzymes are attributed to the concentration of the L‐tyrosinamide substrate by the aptamer units in proximity to the catalytic sites (Kd = (14 ± 0.1) × 10?6 m for all 49‐mer catalysts and Kd = (2.5 ± 0.1) × 10?6 m and Kd = (0.8 ± 0.04) × 10?6 m for the 23‐mer catalysts). Electron spin resonance experiments reveal that ?OH radicals and ascorbate radicals participate in the transformation of tyrosine derivatives to catechol products. An autocatalytic feedback mechanism for the amplified generation of the two radicals is suggested. 相似文献
93.
Effect of different biopolymers and polymers on the mechanical and permeation properties of extruded PHBV cast films
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The biopolymer poly‐3‐hydroxybutyrate‐co‐3‐hydroxyvalerate (PHBV) is a promising material for packaging applications but its high brittleness is challenging. To address this issue, PHBV was blended with nine different biopolymers and polymers in order to improve the processing and mechanical properties of the films. Those biopolymers were TPS, PBAT, a blend of PBAT + PLA, a blend of PBAT + PLA + filler, PCL and PBS, and the polymers TPU, PVAc, and EVA. The extruded cast films were analyzed in detail (melting temperature, crystallinity, mechanical properties, permeation properties, and surface topography). A decrease in crystallinity and Young's modulus and an increase in elongation at break and permeability were observed with increasing biopolymer/polymer concentration. In PHBV‐rich blends (≥70 wt % PHBV), the biopolymers/polymers PCL, PBAT, and TPU increased the elongation at break while only slightly increasing the permeability. Larger increases in the permeability were found for the films with PBS, PVAc, and EVA. The films of biopolymer/polymer‐rich blends (with PBAT, TPU, and EVA) had significantly different properties than pure PHBV. A strong effect on the properties was measured assuming that at certain biopolymer/polymer concentrations the coherent PHBV network is disrupted. The interpretation of the permeation values by the Maxwell–Garnett theory confirms the assumption of a phase separation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46153. 相似文献
94.
Production,nutrient cycling and soil compaction to grazing of grass companion cropping with corn and soybean 总被引:1,自引:0,他引:1
Cristiano M. Pariz Ciniro Costa Carlos A. C. Crusciol Paulo R. L. Meirelles André M. Castilhos Marcelo Andreotti Nídia R. Costa Jorge M. Martello Daniel M. Souza Verena M. Protes Vanessa Z. Longhini Alan J. Franzluebbers 《Nutrient Cycling in Agroecosystems》2017,108(1):35-54
Agricultural management systems are needed to simultaneously enhance production, promote plant diversity, improve nutrient cycling and reduce soil compaction. We investigated the effects of intercropped forage grass on production of corn (Zea mays L.) harvested for silage at 0.20 and 0.45 m height in the summer, as well as on production of subsequent forage, soybean [Glycine max (L.) Merr.] harvested for silage, nutrient cycling and soil responses on a Typic Haplorthox in Botucatu, São Paulo State, Brazil. Palisade grass cv. BRS Piatã [Urochloa brizantha cv. BRS Piatã] was the introduced companion crop with corn (Years 1 and 2), while signal grass [Urochloa decumbens cv. Basilisk] was the residual weedy species in comparison. Guineagrass cv. Aruãna [Megathyrsus maximus cv. Aruãna] was the introduced companion crop with soybean (Year 3), with only a residual effect of crop systems from the previous two years. After the corn silage harvest, pasture was grazed by lambs in winter/spring using a semi-feedlot system. When cut at 0.45 m compared with 0.20 m height, corn intercropped with palisade grass had greater leaf nutrient concentration, improved agronomic characteristics, forage mass of pasture for grazing by lambs, greater surface mulch produced, and greater quantity of N, P and K returned to soil. Greater soil organic matter, P, K and Mg concentration, and base saturation in the surface soil depth and lower soil penetration resistance at all depths occurred at 0.45 m than at 0.20 m corn silage cutting height intercropped with palisade grass. Analyzing the system as a whole, harvesting corn silage crop with palisade grass intercrop at 0.45 m height was the most viable option in this integrated crop-livestock system. 相似文献
95.
Verena Ruhlmann Philipp Heusch Hilmar Kühl Karsten Beiderwellen Gerald Antoch Michael Forsting Andreas Bockisch Christian Buchbender Harald H. Quick 《Magma (New York, N.Y.)》2016,29(2):301-308
Objective
To evaluate the influence of Gadolinium contrast agent on image segmentation in magnetic resonance (MR)-based attenuation correction (AC) with four-segment dual-echo time Dixon-sequences in whole-body [18F]-fluorodeoxyglucose positron emission tomography (PET)/MR imaging, and to analyze the consecutive effect on standardized uptake value (SUV).Materials and methods
Hybrid imaging with an integrated PET/MR system was performed in 30 oncological patients. AC was based on MR imaging with a Dixon sequence with subsequent automated image segmentation. AC maps (µmaps) were acquired and reconstructed prior to (µmap?gd) and after (µmap+gd) Gd-contrast agent application. For quantification purposes, the SUV of organs and tumors based on both µmaps were compared.Results
Tissue classification based on µmap?gd was correct in 29/30 patients; based on µmap+gd, the brain was falsely classified as fat in 12/30 patients with significant underestimation of SUV. In all cancerous lesions, tissue segmentation was correct. All concordant µmaps?gd/+gd resulted in no significant difference in SUV.Conclusion
In PET/MR, Gd-contrast agent potentially influences fat/water separation in Dixon-sequences of the head with above-average false tissue segmentation and an associated underestimation of SUV. Thus, MR-based AC should be acquired prior to Gd-contrast agent application. Additionally, integrating the MR-based AC maps into the reading-routine in PET/MR is recommended to avoid interpretation errors in cases where tissue segmentation fails.96.
Analysis of composite beams with consideration of semi‐rigid, ductile connections. Often composite connections don't have the full bending resistance of the connected composite beam and are in addition not fully rigid. But on the other side the bending resistances and the stiffnesses in the joints are too large to ignore. This article presents a simplified model, which allows to analyse the composite beam including the connection taking into account the effects of the connection as a bilinear spring. 相似文献
97.
98.
99.
Chi Ma Verena Martinez-Rodriguez Peter R. Hoffmann 《International journal of molecular sciences》2021,22(20)
The selenoprotein family includes 25 members, many of which are antioxidant or redox regulating enzymes. A unique member of this family is Selenoprotein I (SELENOI), which does not catalyze redox reactions, but instead is an ethanolamine phosphotransferase (Ept). In fact, the characteristic selenocysteine residue that defines selenoproteins lies far outside of the catalytic domain of SELENOI. Furthermore, data using recombinant SELENOI lacking the selenocysteine residue have suggested that the selenocysteine amino acid is not directly involved in the Ept reaction. SELENOI is involved in two different pathways for the synthesis of phosphatidylethanolamine (PE) and plasmenyl PE, which are constituents of cellular membranes. Ethanolamine phospholipid synthesis has emerged as an important process for metabolic reprogramming that occurs in pluripotent stem cells and proliferating tumor cells, and this review discusses roles for upregulation of SELENOI during T cell activation, proliferation, and differentiation. SELENOI deficiency lowers but does not completely diminish de novo synthesis of PE and plasmenyl PE during T cell activation. Interestingly, metabolic reprogramming in activated SELENOI deficient T cells is impaired and this reduces proliferative capacity while favoring tolerogenic to pathogenic phenotypes that arise from differentiation. The implications of these findings are discussed related to vaccine responses, autoimmunity, and cell-based therapeutic approaches. 相似文献
100.
6‐Dihydroparadol,a Ginger Constituent,Enhances Cholesterol Efflux from THP‐1‐Derived Macrophages
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Dongdong Wang Verena Hiebl Angela Ladurner Simone L. Latkolik Franz Bucar Elke H. Heiß Verena M. Dirsch Atanas G. Atanasov 《Molecular nutrition & food research》2018,62(14)