L'influence de la double couche électrochimique sur la réduction de quelques anions oxygénés

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Le comportement polarographique de l'ion chromate. I. Élucidation du mécanisme réactionnel et étude de l'influence de l'électrolyte-support

The polarographic reduction of the chromate ion may proceed along two different paths (direct discharge, or antecedent chemical reaction), both strongly influenced by the electrical characteristics of the interphase. The "true" rate constants of the processes have been evaluated, taking into account the presence of the double layer, and the adsorbability of the chromate ion. © 1962.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Double couche electrochimique et cinetique des reactions d'electrode. Elucidation du mode d'action des cations tetraalkylammonium

The kinetic study of various electrode reactions shows, in agreement with previous Russian work, that the action of the tetraalkylammonium ions can be explained, in absence of any complementary supporting electrolyte, in terms of a static ψ effect, generally complicated by blocking of the surface. In presence of an excess of supporting electrolyte however, another retarding process is observed, which, essentially depends on the nature of the supporting anion. It has been shown that this anionic effect does not follow the order of increasing adsorbability on mercury, but more likely results from direct interaction between these anions and the tetraalkylammonium cations (although co-operative adsorption may be an additional effect at electrode potentials on the negative side but not too far from the point of zero charge). The nature of this interaction is discussed, with special reference to the perchlorate ion, which exhibits the largest effect. © 1965.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Distribution of clinical risk factors for fracture in a Brussels cohort of postmenopausal women: The FRISBEE study and comparison with other major cohort studies

Objectives The estimation of fracture risk using clinical risk factors (CRFs) is of primary concern in osteoporosis management, but only some risk factors have been thoroughly evaluated and incorporated in predictive models. We have launched a large prospective study, the ‘Fracture Risk Brussels Epidemiological Enquiry’ (FRISBEE), to develop a new predictive model for osteoporotic fractures. The aims of this report are to describe the methodology of the FRISBEE study and to compare the distribution of CRFs in our cohort with those reported in other large studies. Study design FRISBEE is a new study that prospectively evaluates a cohort of 3560 post-menopausal women (aged 60–85 years) followed yearly for the occurrence of fragility fractures. Multiple validated CRFs, densitometry (DXA) values and intake of medication were systematically registered at baseline. The distribution of the FRISBEE CRFs has been compared with the distributions of CRFs in the cohorts used to develop the FRAX® model as well as in more recent cohorts. For these recent cohorts, we focused on CRFs not included in FRAX®. Results The most frequently encountered CRFs used in FRAX® were a prior fragility fracture (27.1%) and a parental history of hip fracture (13.4%). The prevalence of some CRFs not integrated in FRAX® was relatively high, such as the use of proton pump inhibitors (20.8%) and a history of fall(s) (19.7%). The prevalence of many CRFs was quite variable between cohorts; for example, the prevalence of ‘personal prior fragility fracture’ ranged from 9% to 51%. Conclusion We found considerable heterogeneity in the prevalence of CRFs between cohort studies. The impact of these differences on the predictive value of a particular CRF is unknown. We will construct a predictive model calibrated to the Belgian population. More importantly, the FRISBEE study should allow us to determine the predictive value of newly recognized CRFs in addition to the FRAX® algorithm to reliably estimate fracture risk.SCOPUS: ar.jinfo:eu-repo/semantics/inPres

Covid-19 dans la ville de Kinshasa : Représentations sociales chez les fugitifs du confinement.

International audienceUpon the announcement of lockdown of Kinshasa (The capital city of the Democratic Republic of Congo) due to increase cases of corona virus infections, a wave of fear and concern arose among the population of the city causing a massive population’s displacement towards neighboring provinces. This is to contextualize a phenomenological qualitative study exploring the social representation of COVID-19, the motivations influencing the shift of population and the discourses of the subjects on the care strategies, or “therapeutic artifacts” proposed by this population of Kinshasa. The analysis of 19 semi-structured interviews highlighted the presence of five categories of representations of COVID-19: imaginary disease, disease for businessmen, invention for demographic purposes, war between states and, divine punishment. In addition, four types of motivation have influenced the movement of the population: socioeconomic crisis, insecurity, ban of churches and, easy access to traditional treatment. This study finally shows that the fugitive population uses traditional therapies (herbalists and traditional beliefs, including prayers and sorcery) to cope with this pandemic. Improving knowledge, strengthening the communication system and interventions aimed at changing social representations causing negative images of COVID-19 are recommended

Leukemia

International audienceNo abstract availabl

Interlaboratory development and validation of a HRM method applied to the detection of JAK2 exon 12 mutations in polycythemia vera patients.

BACKGROUND: Myeloproliferative disorders are characterized by clonal expansion of normal mature blood cells. Acquired mutations giving rise to constitutive activation of the JAK2 tyrosine kinase has been shown to be present in the majority of patients. Since the demonstration that the V617F mutation in the exon 14 of the JAK2 gene is present in about 90% of patients with Polycythemia Vera (PV), the detection of this mutation has become a key tool for the diagnosis of these patients. More recently, additional mutations in the exon 12 of the JAK2 gene have been described in 5 to 10% of the patients with erythrocytosis. According to the updated WHO criteria the presence of these mutations should be looked for in PV patients with no JAK2 V617F mutation. Reliable and accurate methods dedicated to the detection of these highly variable mutations are therefore necessary. METHODS/FINDINGS: For these reasons we have defined the conditions of a High Resolution DNA Melting curve analysis (HRM) method able to detect JAK2 exon 12 mutations. After having validated that the method was able to detect mutated patients, we have verified that it gave reproducible results in repeated experiments, on DNA extracted from either total blood or purified granulocytes. This HRM assay was further validated using 8 samples bearing different mutant sequences in 4 different laboratories, on 3 different instruments. CONCLUSION: The assay we have developed is thus a valid method, adapted to routine detection of JAK2 exon 12 mutations with highly reproducible results

Clinical and biological data of 8 patients with exon 12 mutations tested in 4 laboratories (RCM: Red cell mass. ND: Not done).

<p>Clinical and biological data of 8 patients with exon 12 mutations tested in 4 laboratories (RCM: Red cell mass. ND: Not done).</p