Search results for "Molecules"
showing 10 items of 1147 documents
Detailed Analysis of Packing Efficiency Allows Rationalization of Solvate Formation Propensity for Selected Structurally Similar Organic Molecules
2018
In structural study of seven bile acids it was identified that their propensity for solvate formation is directly related to the packing efficiency of the unsolvated phases: low packing index, voids, and unsatisfied hydrogen bonding lead to extensive solvate formation, whereas efficient packing leads to the opposite. This was determined to be caused by the presence of OH group attached to carbon C12. Solvate formation was determined to provide a noticeable improvement in the packing efficiency for compounds having ansolvates with inefficient packing.
Rational linkage of magnetic molecules using click chemistry
2015
Established CuAAC click reactions are used for the first time to assemble magnetic molecules to an extended molecular arrangement. This novel synthetic approach is expected to be a general approach to link SMMs as an important precondition to realize quantum computing.
Dynamic Molecular Graphs: “Hopping” Structures
2013
This work aims to contribute to the discussion about the suitability of bond paths and bond-critical points as indicators of chemical bonding defined within the theoretical framework of the quantum theory of atoms in molecules. For this purpose, we consider the temporal evolution of the molecular structure of [Fe{C(CH2 )3 }(CO)3 ] throughout Born-Oppenheimer molecular dynamics (BOMD), which illustrates the changing behaviour of the molecular graph (MG) of an electronic system. Several MGs with significant lifespans are observed across the BOMD simulations. The bond paths between the trimethylenemethane and the metallic core are uninterruptedly formed and broken. This situation is reminiscen…
The Zwitterion [8,8′-μ-CH2O(CH3)-(1,2-C2B9H10)2-3,3′-Co]0 as a Versatile Building Block To Introduce Cobalt Bis(Dicarbollide) Ion into Organic Molecu…
2012
The synthesis of a new bridged [8,8′-μ-CH2O(CH3)-(1,2-C2B9H10)2-3,3′-Co]0 derivative (2), arising from the acid-catalyzed reaction of cobalt bis(1,2-dicarbollide)(1−) ion with formaldehyde, is reported. The proposed reaction path is supported by the isolation of side products including two zwitterionic compounds, the known bridged [8,8′-μ-(CH3O)-(1,2-C2B9H10)2-3,3′-Co]0 derivative (3), the new zwitterion [(8-(CH3)2O-1,2-C2B9H10)-(1′,2′-C2B9H11)-3,3′-Co]0 (4), and two anionic compounds—the known [(8,8′-Cl2-1,2-C2B9H10)2-3,3′-Co]− and the newly characterized dimethoxy derivative [(8,8′-(CH3O)2-1,2-C2B9H10)2-3,3′-Co]− of the cobalt bis(dicarbollide) ion. Compound 2 serves as a versatile buildi…
Quantitative Characterization of the Local Electrophilicity of Organic Molecules. Understanding the Regioselectivity on Diels−Alder Reactions
2002
Regional electrophilicity at the active sites of the reagents involved in polar Diels−Alder processes may be described on a quantitative basis using an extension of the global electrophilicity inde...
Activation of PPARβ/δ inhibits leukocyte recruitment, cell adhesion molecule expression, and chemokine release
2009
Abstract Activation of the nuclear receptor PPARb/d inhibits acute inflammatory responses in vitro with human primary cells and in vivo by targeting the endothelial cell-leukocyte interaction. The infiltration of PMNs into tissues is a prominent feature in inflammation. The mechanism underlying PMN recruitment depends on the release of chemotactic mediators and CAM expression on endothelial cells. The nuclear receptor PPARβ/δ is widely expressed in many tissues, including the vascular endothelium; however, its role in acute inflammation remains unclear. Using intravital microscopy in the mouse cremasteric microcirculation, we have shown that activation of PPARβ/δ by its selective ligand GW5…
Hypothermic preservation of lung allograft inhibits cytokine-induced chemoattractant-1, endothelial leucocyte adhesion molecule, vascular cell adhesi…
2007
Summary Organ dysfunction is a major clinical problem after lung transplantation. Prolonged cold ischaemia and reperfusion injury are believed to play a central role in this complication. The influence of cold preservation on subsequent warm reperfusion was studied in an isolated, ventilated and perfused rat lung. Rat lungs were flushed with cold Perfadex-solution and stored at 4°C for different time periods. Thereafter lungs were perfused and ventilated for up to 3 h. Physiological parameters, production of inflammatory mediators and leucocyte infiltration were measured before and after perfusion. Lungs subjected to a cold ischaemia time of up to 6 h showed stable physiological conditions …
Radical Formation by Fine Particulate Matter Associated with Highly Oxygenated Molecules
2019
Highly oxygenated molecules (HOMs) play an important role in the formation and evolution of secondary organic aerosols (SOA). However, the abundance of HOMs in different environments and their relation to the oxidative potential of fine particulate matter (PM) are largely unknown. Here, we investigated the relative HOM abundance and radical yield of laboratory-generated SOA and fine PM in ambient air ranging from remote forest areas to highly polluted megacities. By electron paramagnetic resonance and mass spectrometric investigations, we found that the relative abundance of HOMs, especially the dimeric and low-volatility types, in ambient fine PM was positively correlated with the formatio…
Synthèses optimisées et caractérisations avancées de nanotubes de titanate et de leurs fonctionnalisations : vers l'élaboration de nanovecteurs de mo…
2017
The aim of this PhD thesis is to develop new nanohybrids based on titanate nanotubes (TiONts) in order to use them as nanocarrier of a therapeutic molecule: a stilbene phenol, 4'-hydroxy-4-(3-aminopropoxy)-trans-stilbene (HAPtS), which is a transresveratrol derivative.TiONts are synthesized by a hydrothermal treatment from a precursor of rutile titanium dioxide. Two methods of hydrothermal synthesis have been studied (the static and dynamic ones): the second approach uses an original hydrothermal device which provides a vigorous mechanical stirring during the hydrothermal process with controllable stirring time par hour. A parametric study was carried out to evaluate the effect of reaction …
Rigid versus Flexible Protein Matrix: Light-Harvesting Complex II Exhibits a Temperature-Dependent Phonon Spectral Density
2018
Dynamics-function correlations are usually inferred when molecular mobility and protein function are simultaneously impaired at characteristic temperatures or hydration levels. In this sense, excitation energy transfer in the photosynthetic light-harvesting complex II (LHC II) is an untypical example because it remains fully functional even at cryogenic temperatures relying mainly on interactions of electronic states with protein vibrations. Here, we study the vibrational and conformational protein dynamics of monomeric and trimeric LHC II from spinach using inelastic neutron scattering (INS) in the temperature range of 20-305 K. INS spectra of trimeric LHC II reveal a distinct vibrational …