Search results for "Activation"

Generation of an Eosinophilotactic Factor from Human PMNs by Various Mechanisms of Cell Activation

1979

It is well established that an increase in the number of eosinophils both in tissue and in the circulation is a feature of many clinical conditions based on delayed (1,2) and immediate type hypersensitivity reactions (3,4). Since eosinophils have been recognised to exert specific killer function on parasites (5) and to be prominent participants at sites of inflammation, the mechanisms of their chemo-attraction are of major importance. In immediate type hypersensitivity reactions, eosinophils have been demonstrated to counteract the mediators of inflammation such as histamine (6), the SRS-A (7) and the platelet aggregating factor (8).

Alfavīrusu vektoru izstrāde makrofāgu aktvācijai vēža imunoterapijā

2016

Audzēju-iefiltrējošiem makrofāgiem piemīt gan spēja veicināt audzēja attīstību, gan inhibēt, attiecībā no to aktivācijas stāvokļa. In vitro pētījumos ir ticis parādīts, ka, iedarbojoties ar interferonu-g (IFN-γ) kopā ar Toll-like receptora (TLR) ligandu, tika ierosināts M1 makrofāgu fenotips, kas tiek asociēts ar audzēja iznīcināšanu. Audzēja imūnterapiju varētu nodrošināt M1 makrofāgu fenotipa inducēšana audzēju-iefiltrējošos makrofāgos. Šajā darbā mēs izvērtējām Semliki meža vīrusa (SFV) vektoru potenciālu makrofāgu aktivācijā pret vēzi. SFV tika izmantots, lai konstruētu replikācijas defektīvus konstruktus ar ieklonētiem peļu audzēja nekrozes faktora (mTNFα), peļu IFNγ un cilvēka IFNγ gē…

A general diastereoselective synthesis of highly functionalized ferrocenyl ambiphiles enabled on a large scale by electrochemical purification

2017

International audience; A general synthesis of highly functionalized ferrocenes, which include (P,B)- and (N,B)-ambiphiles, has been developed at a multigram scale. Diastereoselective stepwise modification of di-tert-butylated ferrocenes included the unprecedented separation of electroactive species. Bulky alkyl groups on ferrocenes ensure planar chirality of ambiphiles and enforce closer proximity of antagonist Lewis functions.

Theoretical evaluation of structures and energetics involved in the hydrogenation of hydrocarbons on palladium surfaces

2001

Abstract Quantum mechanical calculations were employed to deepen information about the basic properties of the mechanism occurring in the palladium catalytic hydrogenation involving surface hydrogen species of unsaturated hydrocarbons. Activation energy values of elementary events implicated in the whole reaction were computed by potential energy surface analyses, to determine the corresponding occurrence probabilities of the same events. Different surface hydrogen species were pointed out and their relevance in the overall surface process was discussed together with their geometrical and chemical characteristics.

Bifunctional coordination polymers as efficient catalysts for carbon dioxide conversion

2019

A chiral molecular conductor: synthesis, structure, and physical properties of [ET]3[Sb2(L-tart)2].CH3CN (ET = bis(ethylendithio)tetrathiafulvalene; …

2004

The salt [ET](3)[Sb(2)(L-tart)(2)].CH(3)CN (1) has been obtained by electrocrystallization of the organic donor bis(ethylendithio)tetrathiafulvalene (ET or BEDT-TTF) in the presence of the chiral anionic complex [Sb(2)(L-tart)(2)](2-) (L-tart = (2R,3R)-(+)-tartrate). This salt crystallizes in the chiral space group P2(1)2(1)2(1) (a = 11.145(2) angstroms, b = 12.848(2) angstroms, c = 40.159(14) angstroms, V = 5750.4(14) angstroms(3), Z = 4) and is formed by alternating layers of the anions and of the organic radicals in a noncentrosymmetric alpha-type packing. This compound shows a room temperature electrical conductivity of approximately 1 S.cm(-1) and semiconducting behavior with an activa…

On the tautomerization process of glycine in aqueous solution

2000

The experimental activation energy for the tautomerization of glycine zwitterion neutral form has been reported to be 14.6 kcalrmol. It has been generally assumed that this energy barrier is needed for proton transfer to occur. However, previous theoretical results do not support this interpretation. In the present work, we examine this question using density functional calculations, extended basis sets and a polarizable continuum solvent model. Our results suggest that the limiting step for the tautomerization process corresponds basically to H-atom reorientation in the -COOH group. This could be a general feature in the tautomerization of amino acids. q 2000 Elsevier Science B.V. All righ…

Apparent activation energies and apparent frequency factor in polarographic waves of paludrine-Zn(II)

1993

Abstract Arrhenius and Vlcek plots of ac 1 and dp polarograms of paludrine-Zn complexes are tested in order to understand the apparent activation energies and pre-exponential factor, and their dependence on the potential. These empirical treatments are useful for obtaining information about the energetic contributions of the elemental processes associated with the Zn(II) and paludrine ligands in the overall mechanism of reduction of the complex 2:1 on the mercury interface.

Magnetic Disaccommodation in Manganese Ferrites in the Temperature Region IV

1991

The magnetic relaxation in polycrystalline, nonstoichiometric manganese ferrite samples MnxFe3−xO4 is investigated as a function of the Mn content (0 ≦ x ≦ 1). The analysis of the experimental results shows that in the temperature region IV two different relaxation processes at 285 (IV) and 220 K (IVa) can be distinguished. The process IV exhibits orientational relaxation characteristics and is composed by the superposition of two Debye processes with activation energies close to 0.75 and 0.80 eV whereas relaxation IV a could be associated with vacancy migration through the lattice, but future investigations are necessary to probe this. Es wird die magnetische Relaxation in polykristallinen…

Synthesis of peptides with α,β‐dehydroamino acids, V. coupling experiments with C‐terminal dehydrophenylalanine and dehydroalanine residues

1986

N-Protected model dipeptides of C-terminal (Z)-ΔPhe and ΔAla couple with glycine esters after activation with either diphenyl phosphorazidate (DPPA), N-cyclohexyl-N′-[2-(N-methylmorpholinio)ethyl]carbodiimide p-toluenesulfonate (WSC), N,N′-dicyclohexylcarbodiimide + 1-hydroxybenzotriazole (DCC + HOBt), or the mixed anhydride (MA) with isobutyl chlorocarbonate to give in good or mostly moderate yields the (Z)-ΔPhe-containing tripeptides 1 – 9 and ΔAla-containing tripeptides 11 – 19, respectively. In the MA and DPPA methods, further acylation products 20a – d are formed to a great extent, expecially during the ΔAla peptide syntheses. (E)-TFA-Gly-ΔPhe and Gly-OtBu, irrespective of the activati…