Study of the Dielectric Relation and the Doping Effect on Conductivity in Lithium Tantalate

Ceramics Li0.98-xTa1.004-x/5NixO3 (LTN) samples have been prepared, for x{0;0.01;0.02;0.05;0.08;0.15;0.2}. Ac impedance measurements were carried out in the frequency range 1Hz-1MHz and from 300°C to 900°C. The influence of Ni doping on dc conductivity was depicted. Through the ac impedance, dielectric constant was deduced and two dielectric relaxations have been clearly identified at high temperature. The low frequency relaxation is attibuted to the space charges, and the high frequency one to ferroelectric dipoles. Systematic fits have been done using the Cole-Cole model. It’s appears for identified relaxations, that at the temperature close to Tc, the dispersion step Δ ε is maximum ; the relaxation time τ is thermally activated and also present an extremum at Tc. The influence of Ni doping on these relaxations, specially the relaxation of the space charges was examinedCeramics Li0.98-xTa1.004-x/5NixO3 (LTN) samples have been prepared, for x{0;0.01;0.02;0.05;0.08;0.15;0.2}. Ac impedance measurements were carried out in the frequency range 1Hz-1MHz and from 300°C to 900°C. The influence of Ni doping on dc conductivity was depicted. Through the ac impedance, dielectric constant was deduced and two dielectric relaxations have been clearly identified at high temperature. The low frequency relaxation is attibuted to the space charges, and the high frequency one to ferroelectric dipoles. Systematic fits have been done using the Cole-Cole model. It’s appears for identified relaxations, that at the temperature close to Tc, the dispersion step Δ ε is maximum ; the relaxation time τ is thermally activated and also present an extremum at Tc. The influence of Ni doping on these relaxations, specially the relaxation of the space charges was examined

Polymorphisme de l’apolipoprotéine E dans la population du nord du Maroc: fréquence et influence sur les paramètres lipidiques

Introduction: L'objectif de ce travail est de déterminer les fréquences alléliques et génotypiques des sites polymorphes situés dans le gène de l'apolipoprotéine E (apo E) ainsi que leur impact sur les paramètres cliniques et lipidiques dans un échantillon de la population du nord du Maroc cliniquement diagnostiqué ADH. Méthodes: Le génotype de l'apo E a été analysé par séquençage direct chez 46 patients cliniquement diagnostiqués ADH selon les critères standards. Résultats: Les fréquences des allèles epsilon 3, epsilon 2 et epsilon 4 ont été respectivement 78.3%, 2.2% et 19.6%. La fréquence de l'allèle epsilon 4 est très élevée chez la population du nord du Maroc en comparaison avec les populations des autres régions marocaines. Elle est similaire à celle rapportée dans les pays de l'Europe du nord. Les taux du cholestérol total, du cholestérol LDL ainsi que la présence des xanthomes et les maladies cardiovasculaires ne différent pas entre les génotypes de l'apoE. En revanche, les résultats ont montré une influence de l'allèle epsilon4 sur le taux des triglycérides chez les sujets obèses. Conclusion: Le génotype de l'apoE ne peut expliquer le phénotype clinique et biochimique présenté par des patients du Nord du Maroc cliniquement diagnostiqués ADH.Key words: Paramètres lipidiques, Maladies cardiovasculaires, Polymorphisme génétique, Gène APO

Effect of heat treatment on bioelectronic coordinates and antibacterial activities of natural and synthetic clays

Our work consists in studying the effect of the thermal treatment at 900°C of three clays “two anionic clays of synthesis ' Double lamellar hydroxide' Zn3Al-CO3 and Mg3Al-CO3, and another natural cationic: Ghassoul (Gh)”, on their antibacterial and bioelectronic power. Their chemical characteristics such as pH at zero charge point (pHzcp), redox potential (Eh), index of oxidizing/reducing power (rH2), and electrochemical potential to dissipate energy (W), as well as the type of oxide formed as a result of this treatment; were also determined. The materials were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and scanning electron microscopy (SEM). Antibacterial activity was tested for four bacteria: two Gram positive (Staphylococcus aureus, Enterococcus faecalis) and two Gram negative (Escherichia coli, Salmonella spp). The antibacterial power of the three clays was evaluated by their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), using the microtiter plate technique. The results showed that the pHzcp, rH2, W and antibacterial power of the two lamellar double hydroxides increased as a result of heat treatment. While the test on the heat treated cationic clay showed an opposite result. It thus appears that the changes in the physicochemical and electrochemical characteristics of the clays following their calcination at 900°C; are at the origin of the change in their antibacterial powe

Analytical and experimental study of electrical conductivity in the lithium tantalate nonstoichiometric structure

We have been interested to experimental and analytical studies of ionic conductivity of nonstoichiometric LiTaO3 solid solutions. Theoretical approach combined with lithium and tantalate vacancy models has been performed. A comparative study between the calculated and measured values is presented taking into account the temperature and composition effects on the conductivity.We have been interested to experimental and analytical studies of ionic conductivity of nonstoichiometric LiTaO3 solid solutions. Theoretical approach combined with lithium and tantalate vacancy models has been performed. A comparative study between the calculated and measured values is presented taking into account the temperature and composition effects on the conductivity

First and second-order derivatives for CP and INDSCAL

In this paper we provide the means to analyse the second-order differential structure of optimization functions concerning CANDECOMP/PARAFAC and INDSCAL. Closed-form formulas are given under two types of constraint: unit-length columns or orthonormality of two of the three component matrices. Some numerical problems that might occur during the computation of the Jacobian and Hessian matrices are addressed. The use of these matrices is illustrated in three applications. (C) 2010 Elsevier B.V. All rights reserved

Tumeurs des deux surrénales. A propos d’un cas

Les tumeurs surrénaliennes bilatérales sont rares. Nous rapportons un cas de phéochromocytome surrénalien associé à un corticosurrénalome controlatéral chez une patiente de 65 ans. L’association d’une hypertension artérielle à des céphalées, sueurs, et palpitations a orienté vers le diagnostic de phéochromocytome. Le bilan biologique basé sur le dosage urinaire des dérivés méthoxylés a confirmé ce diagnostic. L’échographie et le scanner ont montré la présence de deux massessurrénaliennes bilatérales de structure tissulaire. Les deux masses sont discrètement rehaussées après injection du produit de contraste. Devant ce tableau clinique, biologique et morphologique, le diagnostic de phéochromocytome surrénalien bilatéral est retenu. Par conséquent unesurrénalectomie bilatérale par voie bi-sous-costale a été réalisée. L’examen anatomopathologique a révélé la coexistence d’un phéochromocytome sur la pièce de surrénalectomie droite et d’un carcinome corticosurrénalien sur la pièce de surrénalectomie gauche, ce qui était imprévu. Les suites opératoires ont été bonnes, sans récidive, avec un recul de 4 ans. A la lumière de cette observation et d’une revue de la littérature, nous discutons les différentes  caractéristiques de cetteassociation inhabituelle

Application of the JJ-matrix Method to Faddeev-Merkuriev equation: beyond pseudostates

A version of the $J$-matrix method for solving numerically the three-body Faddeev-Merkuriev differential equations is proposed. This version allows to take into account the full spectrum of the two-body Coulomb subsystem. As a result, a discrete analog of the Lippmann-Schwinger equation is obtained which allows to interpret correctly the three-body wave function in two-body domains. The scheme is applied to calculations of the fully resolved absolute differential cross sections for the He$(e,2e)$He$^+$ and He$(e,3e)$He$^{++}$ reactions at small energy and momentum transfers. The results are in good agreement with the experiment both in shape and in absolute value.Comment: 22 pages, 7 figure

Shared detection of Porphyromonas gingivalis in cohabiting family members: a systematic review and meta-analysis

Introduction: Periodontitis is an inflammatory dysbiotic disease. Among putative dysbiosis causes, transmission of Porphyromonas gingivalis between individuals of the same family remains unclear. The aim of this systematic review and meta-analysis is to assess the likelihood of shared detection of Porphyromonas gingivalis among cohabiting family members. Methods: A literature search?was conducted on different databases up to September 2018. Articles assessing the presence of P.gingivalis between members of the same family were screened. Only English literature was retrieved, whereas no limits were applied for bacterial sampling and detection methods. Results: Overall, 26 articles published between 1993 and 2017 met the inclusion criteria. Of these, 18 articles were used for meta-analyses. Based on bacterial culture, the likelihood of an intra-familial transmission of P.gingivalis once a member of the family harbors the bacterium is estimated at 63.5% (n = 132 pairs of family members); this drops to 45% when pooling together culture and Polymerase-Chain-Reaction (n = 481 pairs), whereas it is estimated at 35.7% when genotyping is applied (n = 137 pairs). Conclusion: Pooled results suggest that the likelihood of detecting P.gingivalis within within family members is moderately frequent. Personalized periodontal screening and prevention may consider intra-familial co-occurrence of P.gingivalis as feasible

Genetic gain of grain yield and quality in bread wheat cultivars representing 40 years of breeding in Morocco

Background. Knowledge about the genetic gain for fundamental traits over time is essential for a critical assessment and improvement of breeding programs, especially regarding staple crops like bread wheat.Materials and methods. To estimate the genetic gain in bread wheat breeding in Morocco, grain yield (GY) and grain protein content (GPC) data were collected from 12 multi-environment field trials for 20 bread wheat cultivars released between 1980 and 2022.Results and discussion. Analysis of variance highlighted a high significant variability between environments (E), cultivars (G), and a significant G × E interaction (P < 0.001). Based on stability analysis, the modern cultivars released during the two last decades (2002–2012 and 2013–2022) showed the highest performances and wider stability than old ones, especially in low-yielding environments. Genetic gain (GG) for GY was 21.4 kg ha−1 yr−1 (0.75% yr–1) over 4 decades of breeding. This progress was declining when advancing in decades and ranged from 11% (from 1980–1990 to 1991–2001) to less than 7% (from 2002–2012 to 2013–2022). The GG in low and intermediate yielding environments were the most important (17.34% and 6.88% yr–1 respectively), while GG was nonsignificant in high-yielding environments (4.62% yr–1). Within the same period, GPC showed a nonsignificant negative trend of –0.007% (–0.002% yr–1), while derivative parameters from GY and GPC indicated high positive genetic progress. More efforts should be deployed to implement a good balance between yield performance and quality in the new released cultivars despite the negative correlation between these two traits (r = –0.36; P < 0.001).Conclusion. Adopting advanced technologies, like genomic selection, adequate agronomic practices, and more efficient selection criteria are essential steps to further increase simultaneously grain yield and quality traits