Search results for "init"
showing 10 items of 6629 documents
Counter-complementarity control of the weak exchange interaction in a bent {Ni(ii)3 complex with a μ-phenoxide-μ-carboxylate double bridge
2019
We have prepared and structurally characterized a novel {Ni3} bent complex bearing a double μ-phenoxide-μ-carboxylate bridge. Both terminal Ni(ii) sites are symmetry related, offering a simplified exchange interaction scheme. DC magnetic data is consistent with a weak antiferromagnetic interaction between the central and terminal Ni(ii) ions. As expected for a Ni(ii) system, local zero-field splitting is observed, which can be experimentally established. Broken symmetry quantum chemical calculations, as well as ab initio CASSCF-SA-SOC computations that support the magnetic experimental data, were also performed. From the analysis of other reported closely related Ni(ii) systems, a counter-c…
Equations-of-motion approach to the spin-12Ising model on the Bethe lattice
2006
We exactly solve the ferromagnetic spin- 1/2 Ising model on the Bethe lattice in the presence of an external magnetic field by means of the equations of motion method within the Green's function formalism. In particular, such an approach is applied to an isomorphic model of localized Fermi particles interacting via an intersite Coulomb interaction. A complete set of eigenoperators is found together with the corresponding eigenvalues. The Green's functions and the correlation functions are written in terms of a finite set of parameters to be self-consistently determined. A procedure is developed that allows us to exactly fix the unknown parameters in the case of a Bethe lattice with any coor…
Corte edu e Corte costituzionale tra operazioni di bilanciamento e precedente vincolante. Spunti teorico-generali e ricadute penalistiche (pt.II)
2019
Questo articolo è suddiviso in tre parti e si occupa delle interazioni complesse che si instaurano tra bilanciamenti di competenza della Corte edu e bilanciamenti di competenza della Corte costituzionale sul terreno dei conflitti tra diritti convenzionali e interessi costituzionalmente rilevanti tutelati dal sistema penale nazionale. La prima parte dell’articolo si concentra su un primo possibile modello di bilanciamento riscontrabile nella prassi applicativa del giudice sovranazionale, e cioè il bilanciamento ad hoc (o “caso per caso”); e arriva alla conclusione per cui, in questa prima famiglia di strategie decisionali, la Corte europea, rompendo la c.d. “connessione necessaria diritti/in…
Solid state structural studies of five bile acid derivatives
2008
Five synthetically important bile acid derivatives have been characterized by 13 C CP-MAS, X-ray diffraction (both single crystal and powder), FTIR, and thermoanalytical (DSC and TG) methods. The crystallinity of all these derivatives is high, which can be deducted from the 13 C CP-MAS and powder X-ray diffraction data. Two of the compounds showed polymorphism, and one polymorph was structurally elucidated for both by comparing single crystal and powder X-ray diffraction data.
A full conformational space analysis of bilirubin
2009
Ab initio methods were utilized in a gas-phase systematic conformational search of bilirubin conformers. The whole molecule was divided into four fragments. Most stable conformers of them were employed to build 196 conformers of the complete bilirubin molecule. Initial geometries were optimized using HF/3-21G level of theory and the minimum energy conformers were then reoptimized at B3LYP/6-31G(d) level. Ridge-tile conformer was the most stable one, in perfect agreement with X-ray data. We found that while tetrapyrrole backbone shows some flexibility, propionic acid side chains have a greater influence in bilirubin conformation because they can interact through different hydrogen bond patte…
Isolation of the Endothelin B Receptor from Bovine Lung Structure, Signal Sequence, and Binding Site
1995
Bovine lung endothelin-B receptor has been isolated in good yield with a new procedure involving the use of endothelin-1 coupled to iminobiotin with a long spacer and avidin-agarose affinity chromatography. Contrary to previous reports, evidence has been obtained that the native form of this receptor corresponds to the full-length transcript expected on the basis of cDNA clones. The binding of endothelin to a variety of shortened fragments of the full receptor suggests that the long N-terminal sequence of this receptor has very little influence on the binding of endothelin and that the main determinants of the endothelin binding site might be constituted by residues in the sixth, and possib…
The structural effect between the output module and chromophore-binding domain is a two-way street via the hairpin extension.
2022
AbstractSignal transduction typically starts with either ligand binding or cofactor activation, eventually affecting biological activities in the cell. In red light-sensing phytochromes, isomerization of the bilin chromophore results in regulation of the activity of diverse output modules. During this process, several structural elements and chemical events influence signal propagation. In our study, we have studied the full-length bacteriophytochrome from Deinococcus radiodurans as well as a previously generated optogenetic tool where the native histidine kinase output module has been replaced with an adenylate cyclase. We show that the composition of the output module influences the stabi…
Synthesis of a New Disulfide Affinity Adsorbent for Purification of Human Uterine Progesterone Receptor
2005
For purification of the human uterine progesterone receptor, an affinity adsorbent was synthesized in which the specific ligand (16 alpha-ethyl-3-oxo-19nor-androst-4-ene 17 beta-carboxylic acid) was bound to derivatized celulose using a disulfide-group-containing spacer. The purified receptor protein, isolated by reductive cleavage of the disulfide bond, bound the synthetic gestagen R5020 with high affinity (Kd 12.2 nmol/l). The affinity gel was highly efficient. A 24000-fold purification of progesterone receptor with a recovery of 40% could be achieved in a single step within 6 h. By means of dodecyl sulphate/polyacrylamide gel electrophoresis two main polypeptides with molecular weights o…
The droplet evaporation/condensation transition in a finite volume
2003
A fluid in the NVT ensemble at T less than the critical temperature T_c and rho = N/V somewhat in excess of rho_coex (density of the saturated gas in the gas-liquid transition) is considered. For V->infinity, a macroscopic liquid droplet coexists with surrounding saturated gas according to the lever rule. For finite V, droplets can only exist if they exceed a minimum size. A (rounded) first order transition of the system occurs when the droplet evaporates into the supersaturated gas.Simulation evidence for this transition is given for a Lennard-Jones model and interpreted by a phenomenological theory. At the transition, the chemical potential difference mu_t-mu_coex scales like L^(-d/(d+…
The role of nutrients in the biodegradation of 2,4,6-trinitrotoluene in liquid and soil.
2011
The widely used explosive 2,4,6-trinitrotoluene (TNT) has residues that are potentially explosive, toxic, and mutagenic. TNT and other explosives can be degraded by microorganisms; however, biostimulation is needed for process efficiency. To investigate the effectiveness of using biostimulation to degrade TNT, we added varying concentrations of a nutrient amendment consisting of inorganic salts, plant extracts, and molasses to soil and liquid media. For the inoculum we used a consortium of bacteria AM 06 that had exhibited the ability to degrade TNT and which had been previously isolated from explosives-contaminated soils. Phylogenetically, the clones clustered into seven different genera: …