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61.
Nir Sukenik Francesco Tassinari Shira Yochelis Oded Millo Lech Tomasz Baczewski Yossi Paltiel 《Molecules (Basel, Switzerland)》2020,25(24)
The spin–spin interactions between chiral molecules and ferromagnetic metals were found to be strongly affected by the chiral induced spin selectivity effect. Previous works unraveled two complementary phenomena: magnetization reorientation of ferromagnetic thin film upon adsorption of chiral molecules and different interaction rate of opposite enantiomers with a magnetic substrate. These phenomena were all observed when the easy axis of the ferromagnet was out of plane. In this work, the effects of the ferromagnetic easy axis direction, on both the chiral molecular monolayer tilt angle and the magnetization reorientation of the magnetic substrate, are studied using magnetic force microscopy. We have also studied the effect of an applied external magnetic field during the adsorption process. Our results show a clear correlation between the ferromagnetic layer easy axis direction and the tilt angle of the bonded molecules. This tilt angle was found to be larger for an in plane easy axis as compared to an out of plane easy axis. Adsorption under external magnetic field shows that magnetization reorientation occurs also after the adsorption event. These findings show that the interaction between chiral molecules and ferromagnetic layers stabilizes the magnetic reorientation, even after the adsorption, and strongly depends on the anisotropy of the magnetic substrate. This unique behavior is important for developing enantiomer separation techniques using magnetic substrates. 相似文献
62.
Enrico Luchinat Letizia Barbieri Matteo Cremonini Alessio Nocentini Claudiu T. Supuran Lucia Banci 《Angewandte Chemie (International ed. in English)》2020,59(16):6535-6539
Structure‐based drug development is often hampered by the lack of in vivo activity of promising compounds screened in vitro, due to low membrane permeability or poor intracellular binding selectivity. Herein, we show that ligand screening can be performed in living human cells by “intracellular protein‐observed” NMR spectroscopy, without requiring enzymatic activity measurements or other cellular assays. Quantitative binding information is obtained by fast, inexpensive 1H NMR experiments, providing intracellular dose‐ and time‐dependent ligand binding curves, from which kinetic and thermodynamic parameters linked to cell permeability and binding affinity and selectivity are obtained. The approach was applied to carbonic anhydrase and, in principle, can be extended to any NMR‐observable intracellular target. The results obtained are directly related to the potency of candidate drugs, that is, the required dose. The application of this approach at an early stage of the drug design pipeline could greatly increase the low success rate of modern drug development. 相似文献
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Enrico Albizzati Umberto Giannini Gianpiero Morini Maurizio Galimberti Luisa Barino Raimondo Scordamaglia 《Macromolecular Symposia》1995,89(1):73-89
The role of Lewis bases in MgCl2 supported catalysts for olefin polymerization is a subject of continuous interest and discussion in order to obtain more and more active and stereospecific catalysts and to explain their stereoregulating mechanism. Through molecular calculation and conformational analysis it was possible to identify chelating diethers that have the correct oxygen-oxygen distance necessary to tightly coordinate with the Mg ions of the support, even in the presence of other strong Lewis acids, and unable to give secondary reactions with TiCl4, AlR3, Ti-C and Ti-H bonds. The use of these donors has allowed the synthesis of catalytic systems that are both highly active and stereospecific even in the absence of external donors. Kinetic data of propylene polymerization with these catalyst systems are reported. The importance of the distance between the donor atoms in bifunctional Lewis bases has been proved also in the case of new classes of internal donors. Molecular modelling studies have enabled us to formulate models of active sites, located on some corners of MgCl2 crystallites, whose chirality is induced by the presence of a donor molecule in their environment. These models could explain, at least in part, the exceptional increase of isotactic polymer productivity observed for stereospecific catalyst systems, containing only the internal donor, with respect to catalysts lacking the Lewis base and could account for the influence of the donor on the molecular properties of the obtained polymers. 相似文献
65.
Aurelio Liguori Enrico Armentani Alcide Bertocco Andrea Formato Arcangelo Pellegrino Francesco Villecco 《Entropy (Basel, Switzerland)》2020,22(11)
This article lists some tips for reducing gear case noise. With this aim, a static analysis was carried out in order to describe how stresses resulting from meshing gears affect the acoustic emissions. Different parameters were taken into account, such as the friction, material, and lubrication, in order to validate ideas from the literature and to make several comparisons. Furthermore, a coupled Eulerian–Lagrangian (CEL) analysis was performed, which was an innovative way of evaluating the sound pressure level of the aforementioned gears. Different parameters were considered again, such as the friction, lubrication, material, and rotational speed, in order to make different research comparisons. The analytical results agreed with those in the literature, both for the static analysis and CEL analysis—for example, it was shown that changing the material from steel to ductile iron improved the gear noise, while increasing the rotational speed or the friction increased the acoustic emissions. Regarding the CEL analysis, air was considered a perfect gas, but its viscosity or another state equation could have also been taken into account. Therefore, the above allowed us to state that research into these scientific fields will bring about reliable results. 相似文献
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Loss aversion with multiple investment goals 总被引:1,自引:0,他引:1
Enrico G. De Giorgi 《Mathematics and Financial Economics》2011,5(3):203-227
This paper presents a time-continuous portfolio selection model with loss averse investors, who possess multiple investment
goals at different time horizons. The model assumes partial narrow framing. Investors follow a two-step approach. First, they
optimally allocate wealth among investment goals. Second, they determine an optimal investment strategy for each investment
goal separately. We show that when loss aversion is according to the experimental findings, investors mainly invest their
wealth to reach long-term goals and adopt investment strategies with high leverage to reach short-term goals. The overall
strategy also display high leverage. The same patterns is observed when loss aversion is extreme and goals are very ambitious.
By contrast, when loss aversion is extreme but goals are not too ambitious, investors mainly invest to reach short-term goals
and adopt safe investment strategies for this purpose. 相似文献
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