Search results for "relation"
showing 10 items of 10542 documents
De la cornette au stéthoscope : Histoire infirmière et dimension du sacré
2012
Au travers les siècles qui ont façonné la relation du soin, les hommes et les femmes ont construit la pratique soignante. La charité et l'engagement, ont donné une consistance à une dimension sacrée de la relation. L'histoire de la pensée soignante permet d'appréhender le sens implicite d'une réalité contemporaine d'abord tournée vers l'opérationnalité. Savoir d'où l'on vient c'est savoir qui on est. Chercher à décrypter son histoire professionnelle peut permettre de comprendre ses racines ou plus simplement, de rendre lisible un message perdu aux origines d'un métier.
Building natural science learning through youth science camps
2018
This study focuses on a youth science camp for pupils in sixth to ninth grades that is organized annually by the University of Jyväskylä, Finland. The main idea of the science camp is to learn to do guided inquiry in nature. The study investigates the significance of science camp for encouraging young participants to learn science and how the camp supports their learning. The research method used was a survey. Altogether, 47 youth participated in the camp in 2012 and 2013. The results show that the participants wanted to learn more about science than secondary school could offer, and science camp had a positive impact on their interest in science. It was possible to introduce important conc…
The guanidinium group as a key part of water-soluble polymer carriers for siRNA complexation and protection against degradation.
2014
Here, the preparation of a novel block copolymer consisting of a statistical copolymer N-(2-hydroxypropyl) methacrylamide-s-N-(3-aminopropyl) methacrylamide and a short terminal 3-guanidinopropyl methacrylamide block is reported. This polymer structure forms neutral but water-soluble nanosized complexes with siRNA. The siRNA block copolymer complexes are first analyzed using agarose gel electrophoresis and their size is determined with fluorescence correlation spectroscopy. The protective properties of the polymer against RNA degradation are investigated by treating the siRNA block copolymer complexes with RNase V1. Heparin competition assays confirm the efficient release of the cargo in vi…
Evidence for essential primary amino groups in a bacterial coupling factor F1ATPase.
1980
Abstract We have found that the binding of pyridoxal-5′-phosphate to 6 primary amino groups leads to the inactivation of the enzyme. A preferential reaction of pyridoxal-5′-phosphate with the α-subunits of this enzyme can be demonstrated. The reactivity of the amino groups is influenced by various effectors. In the presence of ATP the inhibition of the ATPase activity is noncompetitive.
Semisynthesis of new tetrahydrofuranic alkyl ester and furano-pyrone derivatives as inhibitors of the mitochondrial complex I
2002
Abstract Methoxymethylation of altholactone ( 1 ) led to the corresponding O -methoxymethyl derivative ( 3 ) in addition to the unexpected 6,7-dihydro-7-methoxy analogue ( 4 ), and two original tetrahydrofuranic (THF) alkyl esters ( 5 , 6 ). Moreover, when we accomplished a new method for the preparation of the furano-pyrone goniofupyrone ( 7 ) through 7-hydroxylation of 1 in acid medium, a minor compound ( 8 ) with an identical skeleton to that of compounds 5 and 6 was identified. Careful examination of the published spectral data of the reported styryl-lactones with an heptolide skeleton reveals that those structures possess also a THF alkyl ester skeleton. The revision of those structure…
Flavanones in Citrus fruit: structure-antioxidant activity relationships
2005
Epidemiological surveys have shown an inverse relationship between the intake of fruit and the incidence of coronary heart disease and some type of cancer. Data found in the literature regarding the flavonoids in general while this study focuses on flavanones, a subclass of flavonoids which occurs in Citrus fruit. The aim of this work is to elucidate the antioxidant or pro-oxidant behaviours of some common flavanones and to determine their activity–structure relationships as antioxidant using the crocin bleaching inhibition assay. The compounds studied were regarding both the aglycon form and the glycoside form. Data evidence that the substitution of the 7th OH group of the flavanones by a …
Synthesis of cyclic dipeptide templates, their incorporation into peptides and studies on their conformational and biological properties.
2009
This study investigated the diastereoselective synthesis of three dipeptide templates 1, 2 and 3, which may be regarded as conformationally restricted analogs of H-Gly-Xaa-OH, in which Xaa constitutes an aromatic amino acid. Bond formation between α-C of Gly and the aromatic moiety was achieved by proton-catalyzed intramolecular electrophilic aromatic substitution. The absolute configuration of the dipeptide templates was determined by single-crystal X-ray crystallography or by nuclear Overhauser enhancement measurements. A protective group strategy was elaborated to allow their incorporation into peptide sequences by liquid phase as well as by solid-phase peptide synthesis. The templates w…
Direct evaluation of the electron density correlation function of partially crystalline polymers
1980
A discussion of the general properties of the one-dimensional electron density correlation function K(z) of a partially crystalline polymer with lamellar structure shows that application of a graphical extrapolation procedure permits direct determination of the crystallinity, the specific inner surface, and the electron density difference ηc − ηa. The procedure is based upon the occurrence of a straight section in the “self-correlation” range of K(z). Curved and nonparallel lamellae do not invalidate the concept. In the case of heterogeneous samples composed of partially crystalline and totally amorphous regions, some of the parameters of the experimentally obtained correlation function, as…
Binding and isomerization energies for the Cu/CN and Cu(I)CN interactions
1993
Abstract Binding and isomerization energies of the CuCN, CuNC, CuCN+, and CuNC+ systems were investigated by means of a multireference CI perturbatively selected, MRCI-PS approach. The inclusion of the main dynamical correlation effects are evaluated. The binding energies for CuCN and CuNC are 4.37 and 4.03 eV, respectively, and those for CuCN+ and CuNC+ are 0.08 and 1.61 eV. Calculated isomerization energies are 7.86 and 35.98 kcal/mol for CuCN and Cu(I)CN isomerizations, respectively.
Dissociation energies within selected configuration interaction and perturbation theory
1993
Abstract Selected configuration interaction (CI) calculations and second-order perturbational theory are used to truncate systematically multireference single and double excitation CI (MRCI) expansions in the calculation of the bond dissociation energies of several systems like the single-bonded LiF molecule or the multiple-bonded N2, NO and O2 diatomic systems. The method is extended to compute the CH bond dissociation energy ofethene C2H4. It is shown how the proposed scheme (perturbation-selected MRCI (MRCI-PS)) is able to reproduce the accuracy of complete MRCI expansions with only a small number of configurations variationally evaluated.