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排序方式: 共有1325条查询结果,搜索用时 15 毫秒
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Prof. Antonio Molinaro Prof. Otto Holst Dr. Flaviana Di Lorenzo Dr. Maire Callaghan Dr. Alessandra Nurisso Dr. Gerardino D'Errico Dr. Alla Zamyatina Prof. Francesco Peri Dr. Rita Berisio Prof. Roman Jerala Prof. Jesús Jiménez‐Barbero Dr. Alba Silipo Prof. Sonsoles Martín‐Santamaría 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(2):500-519
In many Gram‐negative bacteria, lipopolysaccharide (LPS) and its lipid A moiety are pivotal for bacterial survival. Depending on its structure, lipid A carries the toxic properties of the LPS and acts as a potent elicitor of the host innate immune system via the Toll‐like receptor 4/myeloid differentiation factor 2 (TLR4/MD‐2) receptor complex. It often causes a wide variety of biological effects ranging from a remarkable enhancement of the resistance to the infection to an uncontrolled and massive immune response resulting in sepsis and septic shock. Since the bioactivity of lipid A is strongly influenced by its primary structure, a broad range of chemical syntheses of lipid A derivatives have made an enormous contribution to the characterization of lipid A bioactivity, providing novel pharmacological targets for the development of new biomedical therapies. Here, we describe and discuss the chemical aspects regarding lipid A and its role in innate immunity, from the (bio)synthesis, isolation and characterization to the molecular recognition at the atomic level. 相似文献
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Jrme Canivet Elise Bernoud Jonathan Bonnefoy Alexandre Legrand Tanya K. Todorova Elsje Alessandra Quadrelli Caroline Mellot-Draznieks 《Chemical science》2020,11(33):8800
Understanding and controlling molecular recognition mechanisms at a chiral solid interface is a continuously addressed challenge in heterogeneous catalysis. Here, the molecular recognition of a chiral peptide-functionalized metal–organic framework (MOF) catalyst towards a pro-chiral substrate is evaluated experimentally and in silico. The MIL-101 metal–organic framework is used as a macroligand for hosting a Noyori-type chiral ruthenium molecular catalyst, namely (benzene)Ru@MIL-101-NH-Gly-Pro. Its catalytic perfomance toward the asymmetric transfer hydrogenation (ATH) of acetophenone into R- and S-phenylethanol are assessed. The excellent match between the experimentally obtained enantiomeric excesses and the computational outcomes provides a robust atomic-level rationale for the observed product selectivities. The unprecedented role of the MOF in confining the molecular Ru-catalyst and in determining the access of the prochiral substrate to the active site is revealed in terms of highly face-specific host–guest interactions. The predicted surface-specific face differentiation of the prochiral substrate is experimentally corroborated since a three-fold increase in enantiomeric excess is obtained with the heterogeneous MOF-based catalyst when compared to its homogeneous molecular counterpart.Understanding and controlling molecular recognition mechanisms at a chiral solid interface has been addressed in metal–organic framework catalysts for the asymmetric transfer hydrogenation reaction. 相似文献
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Saulius Kaciulis Alessio Mezzi Roberto Montanari Maria Richetta Ekaterina Pakhomova Alessandra Varone 《Surface and interface analysis : SIA》2020,52(12):1093-1097
The W-1%La2O3 alloy has been irradiated by a single laser pulse (λ = 1064 nm) to simulate transient thermal loads of high energy occurring in a tokamak under operative conditions. A zone with a diameter of ~2 mm, namely, much larger than the focal spot, results to be affected by the pulse, and a crater of about 300 μm is observed in its center. La2O3 particles are not present inside the crater. The change of surface morphology is accompanied by elemental redistribution. Multipoint XPS analysis evidenced that the concentration of La is very low in the crater and increases moving toward the border of the affected zone while that of W shows an opposite trend. The composition changes involve only the outmost 5 nm of the sample: through depth profiling, no differences of chemical composition were detected deeper in the alloy between the center and external border of the affected area. 相似文献
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Prof. Alessandra Maria Bossi Prof. Karsten Haupt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(64):14556-14559
Molecularly imprinted polymer nanoparticles (MIP NPs) are antibody-like recognition materials prepared by a template-assisted synthesis. MIP NPs able to target biomolecules, like proteins, are under the spotlight for their great potential in medicine, but efficiently imprinting biological templates is still very challenging. Here we propose generating a molecular imprint in single NPs, by photochemically initiating the polymerization from individual protein templates. In this way, each protein molecule tailors itself its own “polymeric dress”. For this, the template protein is covalently coupled with a photoinitiator, Eosin Y. Irradiated with light at 533 nm, the Eosin moiety acts as an antenna and transfers energy to a co-initiator (an amine), which generates a radical and initiates polymerization. As a result, a polymer network is forming only around the very template molecule, producing cross-linked NPs of 50 nm, with single binding sites showing high affinity (KD 10−9 m ) for their biological target, and selectivity over other proteins. 相似文献
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Nonlinear Dynamics - The nonlinear modes of a non-conservative nonlinear system are sometimes referred to as damped nonlinear normal modes (dNNMs). Because of the non-conservative... 相似文献
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