Search results for "Stack"
showing 10 items of 392 documents
Fluorine Scan of Inhibitors of the Cysteine Protease Human Cathepsin L: Dipolar and Quadrupolar Effects in the π-Stacking of Fluorinated Phenyl Rings…
2016
The π-stacking of fluorinated benzene rings on protein backbone amide groups was investigated, using a dual approach comprising enzyme-ligand binding studies complemented by high-level quantum chemical calculations. In the experimental study, the phenyl substituent of triazine nitrile inhibitors of human cathepsin L (hCatL), which stacks onto the peptide amide bond Gly67-Gly68 at the entrance of the S3 pocket, was systematically fluorinated, and differences in inhibitory potency were measured in a fluorimetric assay. Binding affinity is influenced by lipophilicity (clog P), the dipole and quadrupole moments of the fluorinated rings, but also by additional interactions of the introduced fluo…
Optimized Handover Algorithm Based on Stackelberg Games in CBTC Systems for Urban Rail Transit
2014
Communications Based Train Control (CBTC) systems have become indispensable for train operation to improve the safety and efficiency of train running to the utmost extent at present. In this paper, the problem of train handover in wireless LAN of CBTC systems for urban rail transit was taken into consideration, which was formulated as a market competition with Stackelberg games and cooperative diversity to obtain the reasonable resource allocation for trains. Under the environment of continuous train-to-wayside communications with high reliability, the successful train handover probability was analyzed in detail. Firstly, the relay triggering during handover was introduced, and the price st…
The Bua Group noun class system: Looking for a historical interpretation
2020
International audience; The way Bua languages express number on nouns mostly consists ofalternating suffi xes that bear witness of a former classifi cation system. However,Kulaal is the only present-day language where these markers are not frozen butactually trigger agreement with free, optional determiners that follow the noun andmay show some formal affi nity with its suffi x. For several reasons, previous attemptsat reconstructing a historical noun morphology common to all Bua languagesconsidered the sole suffi xes and neglected the determiners present in Kulaal. But,as is argued in the present paper, more recent data show that, in some cases, presentdaysuffi xes may result from the asso…
Structure and Stability of Racemic and Enantiopure Pimobendan Monohydrates: On the Phenomenon of Unusually High Stability
2017
Study of structures and physicochemical properties of racemic (rac-H) and enantiopure (enant-H) hydrates of the active pharmaceutical ingredient pimobendan revealed that both hydrates have highly similar crystal structures and exhibit unusually high stability. Both structures contain identical two-dimensional layers and very similar conformations. The most significant difference is the stacking of these layers. The high stability of both hydrates appeared as extremely low solubility over a wide temperature range as well as an exceptionally high dehydration temperature and melting point. Study of the dehydration process showed that both hydrates have different activation energies of dehydrat…
Structural versatility of the malonate ligand as a tool for crystal engineering in the design of molecular magnets
2002
The synthesis of ferro- and ferri-magnetic systems with a tunable Tc and three-dimensional (3-D) ordering from molecular precursors implying transition metal ions is one of the active branches of molecular inorganic chemistry. The nature of the interactions between the transition metal ions (or transition metal ions and radicals) is not so easy to grasp by synthetic chemists working in this field since it may be either electrostatic (orbital) or magnetic (mainly dipolar). Therefore, the systems fulfilling the necessary requirements to present the expected magnetic properties are not so easy to design on paper and realize in the beaker. In this work we show how the design of one-, two- and t…
Kinetically Trapped Supramolecular Assembly of Perylene Dianhydride Derivative in Methanol: Optical Spectra, Morphology, and Mechanisms.
2016
Supramolecular self-assembly has attracted increasing attention as a breakthrough methodology in the fields of nanoscience and nanotechnology. Herein, a perylene dianhydride derivative (TP-PDA) self-assembles into well-defined nanospheres through a nucleation-growth process. The mechanisms of this process were explored by using spectral analysis, dynamic light scattering (DLS), and scanning electron microscopy (SEM). In situ DLS and in situ SEM both revealed that the size of the aggregated nanospheres increases with time until the formation of equilibrium H-aggregates. This shows that TP-PDA undergoes a kinetically trapped assembly with a rapid transformation into the thermodynamically favo…
N-(4-Acetyl-3-methyl-1-phenyl-1H-pyrazol-5-yl)-N-methyl-2-(2-methyl-4-oxo-3,4-dihydroquinazolin-3-yl)benzamide
2013
In the title compound, C29H25N5O3, the dihedral angle between the benzene ring and the pendant quinazoline ring system (r.m.s. deviation = 0.036Å) is 87.60 (17)°. The equivalent angle between the pyrazole ring and the phenyl group is 70.0 (2)°. The dihedral angle between the benzene and pyrazole rings is 30.7 (2)° and overall, the molecular conformation approximates to a Z shape. A short intramolecular C—H...O contact occurs. In the crystal, the molecules are linked by Cπ—H...O-type hydrogen bonds and aromatic π–π stacking interactions [centroid–centroid distance = 3.860 (3) Å], generating a three-…
Preliminary Tests On A Miniaturized Hybrid Pv-Pemfc System
2007
A regenerative hybrid PV-PEMFC low power system is a suitable solution to replace batteries and to supply small electric devices placed in remote areas with no grid connection. Such a system was designed and built including a PV array, electrolyzer, PEMFC stack (6We) and hydrogen storage tank. As well known a hybrid PV-PEMFC energy system may represent a reliable solution to the renewable energy storage problem. Hydrogen produced by such a system is a clean fuel, suitable to replace traditional fuels which contain carbon damaging the environment. The paper reports results of a preliminary, non-dynamic experimental analysis performed on the system in order to study the effects of the anode p…
Hydrophobic interactions and stacking forces: A convenient model system
1980
Abstract We consider solvent–biomolecule interactions and the role of solvent structural and isotopic alterations on the thermodynamic stability of biomolecular structures. Approaches to this problem range from the study of biomolecular functional stability, to that of the stability of small structural entities suitable of being taken as model systems for (parts of) larger molecules. We shall focus on this latter case and shall consider the dimerization process of small planar molecules (Methylene Blue). These are a convenient model system for the study of interactions responsible e.g. for base stacking in DNA. As an additional advantage, they do not form hydrogen bonds. The experimental st…
Ontology-based annotation and retrieval of services in the cloud
2014
Cloud computing is a technological paradigm that permits computing services to be offered over the Internet. This new service model is closely related to previous well-known distributed computing initiatives such as Web services and grid computing. In the current socio-economic climate, the affordability of cloud computing has made it one of the most popular recent innovations. This has led to the availability of more and more cloud services, as a consequence of which it is becoming increasingly difficult for service consumers to find and access those cloud services that fulfil their requirements. In this paper, we present a semantically-enhanced platform that will assist in the process of …