Search results for "complex"
showing 10 items of 5889 documents
Mannitol in Amanita muscaria – An osmotic blood–brain barrier disruptor enhancing its hallucinogenic action?
2013
Hypothesis have been made that relatively high level of mannitol present in the tissues of fly agaric (Amanita muscaria) enables more efficient transportation of these active substances into the brain and thus enhance their total activity. It may have been supported by the fact that hallucinogenic effect after A. muscaria consumption is greater than after ingestion of an active substance quantity which the eaten fungi dose contain.
Fine-tuning halogen bonding properties of diiodine through halogen–halogen charge transfer – extended [Ru(2,2′-bipyridine)(CO)2X2]·I2 systems (X = Cl…
2016
The current paper introduces the use of carbonyl containing ruthenium complexes, [Ru(bpy)(CO)2X2] (X = Cl, Br, I), as halogen bond acceptors for a I2 halogen bond donor. In all structures, the metal coordinated halogenido ligand acts as the actual halogen bond acceptor. Diiodine, I2, molecules are connected to the metal complexes through both ends of the molecule forming bridges between the complexes. Due to the charge transfer from Ru–X to I2, formation of the first Ru–X⋯I2 contact tends to generate a negative charge on I2 and redistribute the electron density anisotropically. If the initial Ru–X⋯IA–IB interaction causes a notable change in the electron density of I2, the increased negativ…
Neutral Organometallic Halogen Bond Acceptors: Halogen Bonding in Complexes of PCPPdX (X = Cl, Br, I) with Iodine (I(2)), 1,4-Diiodotetrafluorobenzen…
2012
The behavior of a sterically crowded neutral pincer {2,6-bis[(di-t-butylphosphino)methyl]-phenyl}palladium (PCPPd) halides, PCPPdX (X = Cl, Br or I), as XB acceptors with strong halogen bond (XB) donors, iodine (I2), 1,4-diiodotetrafluorobenzene (F4DIBz), and 1,4-diiodooctafluorobutane (F8DIBu) were studied in the solid state. The co-crystallization experiments afforded high-quality single crystals of XB complexes PCPPdCl–I2 (1a), PCPPdBr–I2 (2a), PCPPdI–I2(3a), PCPPdCl–F4DIBz (1b), PCPPdBr–F4DIBz (2b), and PCPPdBr–F8DIBu (2c). The 1:1 iodine complexes (1a, 2a, and 3a) all showed a strong halogen bonding interaction, the reduction of the sum of the van der Waals radii of halogen to iodine b…
Crystallography of encapsulated molecules.
2017
The crystallography of supramolecular host–guest complexes is reviewed and discussed as a part of small molecule crystallography. In these complexes, the host binds the guests through weak supramolecular interactions, such as hydrogen and halogen bonding, cation–π, anion–π, C–H–π, π–π, C–H–anion interactions and the hydrophobic effect. As the guest often shows severe disorder, large thermal motion and low occupancies, the reliable crystallographic determination of the guest can be very demanding. The analysis of host–guest interactions using tools such as Hirshfeld and cavity volume surface analysis will help to look closely at the most important host–guest interactions. The jewel in the cr…
Modification of the supramolecular structure of [(thione)IY] (Y = Cl, Br) systems by cooperation of strong halogen bonds and hydrogen bonds
2015
Four interhalogen complexes of heterocyclic thione ligands N-methylbenzothiazole-2-thione (mbtt) and 2(3)H-benzothiazole-thione (btt) with strong and tunable S⋯I halogen bonds were synthesized and characterized by X-ray single crystal diffraction. The study of the strength and nature of the interactions was supported by computational analysis using the Quantum Theory of Atoms in Molecules (QTAIM). Halogen bond and hydrogen bond directed self-assemblies of thione compounds were efficiently modified by the changes in the halogen bond donor and acceptor structures. In structures [(mbtt)ICl] (1) and [(mbtt)IBr] (2) the interplay of halogen bonds and hydrogen bonds between the thione hydrogens a…
Correlation at low temperature I. Exponential decay
2003
Abstract The present paper generalizes the analysis in (Ann. H. Poincare 1 (2000) 59, Math. J. (AMS) 8 (1997) 123) of the correlations for a lattice system of real-valued spins at low temperature. The Gibbs measure is assumed to be generated by a fairly general Hamiltonian function with pair interaction. The novelty, as compared to [2,20], is that the single-site (self-) energies of the spins are not required to have only a single local minimum and no other extrema. Our derivation of exponential decay of correlations goes through the spectral analysis of a deformed Laplacian closely related to the Witten Laplacian studied in [2,20]. We prove that this Laplacian has a spectral gap above zero…
Hardy spaces and quasiconformal maps in the Heisenberg group
2023
We define Hardy spaces $H^p$, $00$ such that every $K$-quasiconformal map $f:B \to f(B) \subset \mathbb{H}^1$ belongs to $H^p$ for all $0<p<p_0(K)$. Second, we give two equivalent conditions for the $H^p$ membership of a quasiconformal map $f$, one in terms of the radial limits of $f$, and one using a nontangential maximal function of $f$. As an application, we characterize Carleson measures on $B$ via integral inequalities for quasiconformal mappings on $B$ and their radial limits. Our paper thus extends results by Astala and Koskela, Jerison and Weitsman, Nolder, and Zinsmeister, from $\mathbb{R}^n$ to $\mathbb{H}^1$. A crucial difference between the proofs in $\mathbb{R}^n$ and $\mathbb{…
Planning integrated care at primary care centres: lessons learnt through research in stratification tools in the Valencian Healthcare System
2018
Introduction and policy context: In the Valencian Region social services and the healthcare system are not connected. Also there is not any normative jointly regulating resources, services or aid benefits that would mean an integrated care IC portfolio. Primary care PC centres are the closest and most trustworthy care facility for patients in the Spanish context. Also, PC is one of the most suitable resources to address needs of complex patients, as elderly and/or those with chronic conditions, through an IC approach, but there are some barriers that block its real and effective deployment. Objective and target population: Authors have studied the viability, implementation and development …
Facilitating Access to Health Web Pages with Different Language Complexity Levels
2019
The number of people looking for health information on the Internet is constantly growing. When searching for health information, different types of users, such as patients, clinicians or medical researchers, have different needs and should easily find the information they are looking for based on their specific requirements. However, generic search engines do not make any distinction among the users and, often, overload them with the provided amount of information. On the other hand, specific search engines mostly work on medical literature and specialized web sites are often not free and contain focused information built by hand. This paper presents a method to facilitate the search of he…
Start-Up of Chitosan-Assisted Anaerobic Sludge Bed Reactors Treating Light Oxygenated Solvents under Intermittent Operation
2021
Quality of the granular sludge developed during the start-up of anaerobic up-flow sludge bed reactors is of crucial importance to ensure the process feasibility of treating industrial wastewater such as those containing solvents. In this study, the microbial granule formation from suspended-growth biomass was investigated in two chitosan-assisted reactors. These reactors operated mimicking industrial sites working with night closures treating a mixture of ethanol, ethyl acetate, and 1-ethoxy-2-propanol. Each reactor operated under different hydrodynamic regimes typical from UASB (R1: <